Bug: Remove duplicated card number interface



### Feature Description

The CardNumber interface has a duplicated method with the same functionality.

### Possible Implementation

Remove one of the duplicated interfaces.

### Have you spent some time checking if this feature request 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/api_models/src/payment_methods.rs b/crates/api_models/src/payment_methods.rs
index e045cf2c42d..dd7791ee2d2 100644
--- a/crates/api_models/src/payment_methods.rs
+++ b/crates/api_models/src/payment_methods.rs
@@ -361,7 +361,7 @@ impl From<CardDetailFromLocker> for payments::AdditionalCardInfo {
             card_isin: item.card_isin,
             card_extended_bin: item
                 .card_number
-                .map(|card_number| card_number.get_card_extended_bin()),
+                .map(|card_number| card_number.get_extended_card_bin()),
             card_exp_month: item.expiry_month,
             card_exp_year: item.expiry_year,
             card_holder_name: item.card_holder_name,
diff --git a/crates/cards/src/validate.rs b/crates/cards/src/validate.rs
index 08ad127047c..5a71aaa7863 100644
--- a/crates/cards/src/validate.rs
+++ b/crates/cards/src/validate.rs
@@ -24,7 +24,6 @@ impl CardNumber {
     pub fn get_card_isin(self) -> String {
         self.0.peek().chars().take(6).collect::<String>()
     }
-
     pub fn get_extended_card_bin(self) -> String {
         self.0.peek().chars().take(8).collect::<String>()
     }
@@ -42,9 +41,6 @@ impl CardNumber {
             .rev()
             .collect::<String>()
     }
-    pub fn get_card_extended_bin(self) -> String {
-        self.0.peek().chars().take(8).collect::<String>()
-    }
 }
 
 impl FromStr for CardNumber {
diff --git a/crates/router/src/core/payments/helpers.rs b/crates/router/src/core/payments/helpers.rs
index 1789c3c3fad..38acf574a7c 100644
--- a/crates/router/src/core/payments/helpers.rs
+++ b/crates/router/src/core/payments/helpers.rs
@@ -3719,7 +3719,7 @@ pub async fn get_additional_payment_data(
 
             let card_extended_bin = match enable_extended_bin {
                 Some(config) if config.config == "true" => {
-                    Some(card_data.card_number.clone().get_card_extended_bin())
+                    Some(card_data.card_number.clone().get_extended_card_bin())
                 }
                 _ => None,
             };

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

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

## Description
<!-- Describe your changes in detail -->
The CardNumber interface has a duplicated method with the same functionality. Removed one.
closes #4442
### 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`
-->
1. crates/cards/src/validate
2. crates/router/src/core/blocklist/utils

## 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?
<!--
Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
-->
The methods get_extended_card_bin() and get_card_extended_bin() are identical and thus redundant. It is recommended to keep one and remove the other to avoid confusion.

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

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