feat: Implement major features and fix theming bug

This commit introduces several new features and a critical bug fix.

- Implemented a full "Quick Pay" flow for both within and outside the bank, including IFSC validation, beneficiary verification, and a TPIN-based payment process.
- Added a date range filter to the Account Statement screen and streamlined the UI by removing the amount filters.
- Fixed a major bug that prevented dynamic theme changes from being applied. The app now correctly switches between color themes.
- Refactored and improved beneficiary management, transaction models, and the fund transfer flow to support NEFT/RTGS.

lib/data/models/payment_response.dart

@@ -6,6 +6,7 @@ class PaymentResponse {
   final String? currency;
   final String? errorMessage;
   final String? errorCode;
+  final String? utr;
 
   PaymentResponse({
     required this.isSuccess,
@@ -15,5 +16,6 @@ class PaymentResponse {
     this.currency,
     this.errorMessage,
     this.errorCode,
+    this.utr,
   });
 }