Bugfix/SK-1193 | Handle unknown error, reconnect channel

[Wrede]

This pull request introduces a new test suite for gRPC communication with simulated network conditions using Toxiproxy, and includes several enhancements and refactors in the GrpcHandler class to improve error handling and channel management.

New Test Suite for gRPC Communication:

• Added TestGRPCWithToxiproxy class in .ci/tests/chaos_test.py to test gRPC communication under various network conditions using Toxiproxy.

Enhancements in GrpcHandler:

• Refactored GrpcHandler initialization to include a new _init_channel method and _init_stubs method for better channel and stub management.
• Added logging for gRPC errors in heartbeat, send_heartbeats, and listen_to_task_stream methods to improve error visibility. [1] [2] [3]
• Introduced _handle_unknown_error method to handle non-gRPC specific exceptions by attempting to reconnect and reinitialize stubs.