fix(ws): pass skip_utf8_validation=True to run_forever to survive non-UTF-8 text frames

[tobsh]

Hi maintainers,

Closes #148.

This PR fixes a silent WebSocket failure where WsClient._run_websocket calls wsa.run_forever(...) without skip_utf8_validation=True. When IBKR emits a text-opcode frame containing bytes outside the UTF-8 range (we've observed 0x99 in the wild on order/trade channels), websocket-client's frame decoder raises UnicodeDecodeError inside its receive loop. The run_forever thread then dies before the close handshake completes, on_close never fires, the reconnect path is never triggered, and event delivery stops silently — no error, no reconnect, just a quiet stall.

Passing skip_utf8_validation=True lets raw bytes through to the application layer (where WsClient already wraps message handling in its own try/except), which is consistent with how the upstream websocket-client library expects this case to be handled.

Key changes:

• ibind/base/ws_client.py: pass skip_utf8_validation=True to wsa.run_forever() and a short # why comment naming the failure mode.
• test/integration/base/test_websocket_client_i.py: _verify_started now also asserts skip_utf8_validation=True is passed. Since this helper is shared by every happy-path test in the file (test_start_success, test_start_success_on_second_attempt, test_open_and_close, test_send, test_check_ping, …), the kwarg is regression-pinned. Also extended the local run_forever_exception mock signature in test_open_exception so the new kwarg doesn't TypeError-loop the reconnect path.
• test/integration/base/websocketapp_mock.py: extended the shared run_forever mock signature with skip_utf8_validation: bool = False for the same reason.

Verification:

• pytest test/unit test/integration → 78 passed locally.
• make lint is unchanged on the modified files.

Notes:

• Diff is intentionally minimal: 1 prod kwarg + 3 test/mock signature updates. No new behaviour, no API surface changes.
• We've been running this patch in production for several weeks with no regressions on well-formed frames.

Happy to adjust scope, comment, or test layout based on review.

Thanks!

[Voyz]

LGTM, thanks for the contribution! 🙌