Bug: [BUG]  ListPaymentMethods For Merchant has an empty array of payment_methods_enabled



### Bug Description

While doing a, ListPaymentMethods For Merchant it has an empty array of payment_methods_enabled. 

### Expected Behavior

 ListPaymentMethods For Merchant  should have the payment_methods that has been enabled for that merchant 

### Actual Behavior

ListPaymentMethods For Merchant it has an empty array

### Steps To Reproduce

Provide an unambiguous set of steps to reproduce this bug. Include code or configuration to reproduce, if relevant.
1.Create MA and MCA
2. while making payments do a confirm as false
3. List PaymentMethods For Merchants , the list would be empty for non-card transactions , also the payment_type would be new_mandate/setup_mandate


### Context For The Bug

_No response_

### Environment

Are you using hyperswitch hosted version? Yes/No
If yes, please provide the value of the `x-request-id` response header to help us debug your issue.

If not (or if building/running locally), please provide the following details:
1. Operating System or Linux distribution:
2. Rust version (output of `rustc --version`): ``
3. App version (output of `cargo r --features vergen -- --version`): ``


### Have you spent some time checking if this bug has been raised before?

- [X] I checked and didn't find a similar issue

### Have you read the Contributing Guidelines?

- [X] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

Yes, I am willing to submit a PR!
diff --git a/crates/router/src/core/payment_methods/cards.rs b/crates/router/src/core/payment_methods/cards.rs
index e08dbc61f5e..5797fd60da0 100644
--- a/crates/router/src/core/payment_methods/cards.rs
+++ b/crates/router/src/core/payment_methods/cards.rs
@@ -1823,7 +1823,6 @@ pub async fn list_payment_methods(
         } else {
             api_surcharge_decision_configs::MerchantSurchargeConfigs::default()
         };
-    print!("PAMT{:?}", payment_attempt);
     Ok(services::ApplicationResponse::Json(
         api::PaymentMethodListResponse {
             redirect_url: merchant_account.return_url,
@@ -2070,13 +2069,30 @@ pub async fn filter_payment_methods(
                         })?;
                     let filter7 = payment_attempt
                         .and_then(|attempt| attempt.mandate_details.as_ref())
-                        .map(|_mandate_details| {
-                            filter_pm_based_on_supported_payments_for_mandate(
-                                supported_payment_methods_for_mandate,
-                                &payment_method,
-                                &payment_method_object.payment_method_type,
-                                connector_variant,
-                            )
+                        .map(|mandate_details| {
+                            let (mandate_type_present, update_mandate_id_present) =
+                                match mandate_details {
+                                    data_models::mandates::MandateTypeDetails::MandateType(_) => {
+                                        (true, false)
+                                    }
+                                    data_models::mandates::MandateTypeDetails::MandateDetails(
+                                        mand_details,
+                                    ) => (
+                                        mand_details.mandate_type.is_some(),
+                                        mand_details.update_mandate_id.is_some(),
+                                    ),
+                                };
+
+                            if mandate_type_present || update_mandate_id_present {
+                                filter_pm_based_on_supported_payments_for_mandate(
+                                    supported_payment_methods_for_mandate,
+                                    &payment_method,
+                                    &payment_method_object.payment_method_type,
+                                    connector_variant,
+                                )
+                            } else {
+                                true
+                            }
                         })
                         .unwrap_or(true);
 
diff --git a/crates/router/src/core/payments/operations/payment_create.rs b/crates/router/src/core/payments/operations/payment_create.rs
index 381f0265976..378cbb25467 100644
--- a/crates/router/src/core/payments/operations/payment_create.rs
+++ b/crates/router/src/core/payments/operations/payment_create.rs
@@ -712,7 +712,9 @@ impl PaymentCreate {
             Err(errors::ApiErrorResponse::InvalidRequestData {message:"Only one field out of 'mandate_type' and 'update_mandate_id' was expected, found both".to_string()})?
         }
 
-        let mandate_dets = if let Some(update_id) = request
+        let mandate_details = if request.mandate_data.is_none() {
+            None
+        } else if let Some(update_id) = request
             .mandate_data
             .as_ref()
             .and_then(|inner| inner.update_mandate_id.clone())
@@ -723,8 +725,6 @@ impl PaymentCreate {
             };
             Some(MandateTypeDetails::MandateDetails(mandate_data))
         } else {
-            // let mandate_type: data_models::mandates::MandateDataType =
-
             let mandate_data = MandateDetails {
                 update_mandate_id: None,
                 mandate_type: request
@@ -761,7 +761,7 @@ impl PaymentCreate {
                 business_sub_label: request.business_sub_label.clone(),
                 surcharge_amount,
                 tax_amount,
-                mandate_details: mandate_dets,
+                mandate_details,
                 ..storage::PaymentAttemptNew::default()
             },
             additional_pm_data,

## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [ ] Documentation
- [ ] CI/CD

## Description

ListPaymentMethodsForMerchant was unable to list the payment methods enabled as it was always taking mandate to have Some value even though its respective fields were None. So added a check that, if there's mandate_data present then only any data should be stored in the database

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

<!--
Provide links to the files with corresponding changes.

Following are the paths where you can find config files:
1. `config`
2. `crates/router/src/configs`
3. `loadtest/config`
-->


## Motivation and Context
<!--
Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.

If you don't have an issue, we'd recommend starting with one first so the PR
can focus on the implementation (unless it is an obvious bug or documentation fix
that will have little conversation).
-->


## How did you test it?
- Create MA and MCA 
- Do a payment with confirm as false and then ListPaymentMethodsForMerchnats
> Earlier
![Screenshot 2024-02-01 at 6 15 04 PM](https://github.com/juspay/hyperswitch/assets/55580080/d0b10a50-5694-49e1-93c4-80511fda964c)


> After fix
![Screenshot 2024-02-01 at 6 25 21 PM](https://github.com/juspay/hyperswitch/assets/55580080/685dec2a-061b-4f6a-af93-ba35b9751f60)


## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible
- [ ] I added a [CHANGELOG](/CHANGELOG.md) entry if applicable
