[Bug] Gracefully Handle Horizon RPC Timeouts and 404 Errors

[Menjay7]

Summary

Improve error handling for Horizon RPC requests by gracefully managing timeout scenarios and 404 Not Found responses. This prevents unnecessary application failures, improves user experience, and provides clearer feedback when network or resource issues occur.

Changes
Add dedicated handling for Horizon RPC timeout errors
Add handling for 404 Not Found responses from Horizon endpoints
Prevent unhandled exceptions from propagating to the UI
Implement user-friendly error messages for timeout and missing-resource scenarios
Add retry logic (where appropriate) for transient network failures
Improve logging and diagnostics for Horizon request failures
Standardize RPC error mapping across Horizon integrations
Ensure fallback behavior when Horizon data is temporarily unavailable

Testing
Add unit tests for timeout handling
Add unit tests for Horizon 404 responses
Add integration tests covering:
RPC request timeout scenarios
Missing account/resource lookups
Retry behavior for transient failures
Error propagation and user-facing messaging
Verify application stability under simulated Horizon outages
Motivation

Horizon RPC endpoints can occasionally return timeouts or 404 responses due to network conditions, indexing delays, or missing resources. The application should handle these cases gracefully to avoid crashes, improve reliability, and provide a better user experience.

Checklist
Added timeout handling for Horizon RPC requests
Added graceful handling for 404 Not Found responses
Improved error mapping and logging
Added retry/fallback behavior where appropriate
Added unit and integration tests
Updated documentation and error-handling notes
Verified no regressions in existing Horizon workflows...closed #160

[AlAfiz]

@Menjay7 CI test failed please check it out and fix it