fix: api lock on PaymentsCreate

[dracarys18]

Type of Change

• Bugfix

Description

Added API locking for PaymentsCreate and removed unnecessary get_or_generate_id calls.

Motivation and Context

This fixes race condition when you do PaymentsCreate with confirm=true. A scenario when this can happen is when
you do PaymentsCreate with confirm = true and while it's happening Connector sends a webhook and it updates PaymentAttempt but it hasn't send the response yet so the process is running with old PaymentAttempt state which causes inconsistency.

How did you test it?

• PaymentsCreate with confirm = true to adyen connector which has the above behaviour.
• Check for API locking.

{app=<app-name>} |= `unique_locking_key: \"<payment-id>\", api_identifier: Payments,` |= `src/core/api_locking.rs`

• And sanity test all Payments API.

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code