fix(python): preserve websocket connector options

[luochen211]

Summary

• initialize WebSocketConnector through BaseConnector so common callbacks, middleware, and roots are available
• pass common connector options from create_connector_from_config for ws_url configs
• avoid passing an empty auth object to WebSocketConnector when auth is unset

Tests

• MCP_USE_ANONYMIZED_TELEMETRY=false .venv/bin/python -m pytest tests/unit/test_config.py::TestConnectorCreation::test_create_websocket_connector_preserves_common_options -q
• uv run --extra dev --extra e2b pytest tests/unit/test_config.py -q
• uv run --extra dev ruff check mcp_use/client/config.py mcp_use/client/connectors/websocket.py tests/unit/test_config.py
• uv run --extra dev ruff format --check mcp_use/client/config.py mcp_use/client/connectors/websocket.py tests/unit/test_config.py

Closes #1748