Bug: [BUG] handle empty string updated_by for soft kill kv



### Bug Description

some entries for payment attempt is inserted with '' value in db, in which case we are not sure where the data is present

### Expected Behavior

handle these cases in the safest way by having a lookup in redis and deciding the storage scheme

### Actual Behavior

configured scheme gets picked

### Steps To Reproduce


 tested in integ, not reproducible in local machine

### Context For The Bug

_No response_

### Environment

Are you using hyperswitch hosted version? Yes
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/storage_impl/src/redis/kv_store.rs b/crates/storage_impl/src/redis/kv_store.rs
index 9c429058b70..c39e67eb841 100644
--- a/crates/storage_impl/src/redis/kv_store.rs
+++ b/crates/storage_impl/src/redis/kv_store.rs
@@ -249,7 +249,9 @@ impl<'a> std::fmt::Display for Op<'a> {
         match self {
             Op::Insert => f.write_str("insert"),
             Op::Find => f.write_str("find"),
-            Op::Update(p_key, _, _) => f.write_str(&format!("update_{}", p_key)),
+            Op::Update(p_key, _, updated_by) => {
+                f.write_str(&format!("update_{} for updated_by_{:?}", p_key, updated_by))
+            }
         }
     }
 }
@@ -273,7 +275,8 @@ where
         let updated_scheme = match operation {
             Op::Insert => MerchantStorageScheme::PostgresOnly,
             Op::Find => MerchantStorageScheme::RedisKv,
-            Op::Update(partition_key, field, Some("redis_kv")) => {
+            Op::Update(_, _, Some("postgres_only")) => MerchantStorageScheme::PostgresOnly,
+            Op::Update(partition_key, field, Some(_updated_by)) => {
                 match kv_wrapper::<D, _, _>(store, KvOperation::<D>::HGet(field), partition_key)
                     .await
                 {
@@ -286,11 +289,6 @@ where
             }
 
             Op::Update(_, _, None) => MerchantStorageScheme::PostgresOnly,
-            Op::Update(_, _, Some("postgres_only")) => MerchantStorageScheme::PostgresOnly,
-            _ => {
-                logger::debug!("soft_kill_mode - using default storage scheme");
-                storage_scheme
-            }
         };
 
         let type_name = std::any::type_name::<D>();

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

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

## Description
<!-- Describe your changes in detail -->
there are some entries created with updated_by as '' for payment_attempt, which is causing decide storage scheme to select the configured scheme which is an issue during soft kill with configured scheme as redis_kv as we want db entities to be processed in db

### Additional Changes

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

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## Motivation and Context
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there are some entries created with updated_by as '' for payment_attempt, which is causing decide storage scheme to select the configured scheme which is an issue during soft kill with configured scheme as redis_kv as we want db entities to be processed in db

`select created_at , updated_by from payment_attempt where updated_by = '' order by created_at desc limit 100`

## How did you test it?
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Did you write an integration/unit/API test to verify the code changes?
Or did you test this change manually (provide relevant screenshots)?
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## 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
