Overview
This pull request modernizes the Azure Monitor telemetry integration by switching from the deprecated azure-monitor-events-extension to the OpenTelemetry logging handler. It updates the telemetry event sending logic, improves the handling of reserved log attributes, and refactors tests to match the new implementation. Dependency management and sample requirements are also updated for consistency.

Telemetry integration updates:

• Replaces usage of azure-monitor-events-extension with OpenTelemetry's LoggingHandler for sending telemetry events, introducing a dedicated logger (_event_logger) and initialization logic in _send_telemetry.py. This ensures telemetry events are sent in a more standard and extensible way.
• Updates the track_event and publish_telemetry functions to use the new logging-based approach, including logic to avoid conflicts with reserved log record attributes. [1] [2]
• Updates the TargetingSpanProcessor to check for OpenTelemetry logging support rather than the old extension.

Dependency and configuration changes:

• Updates the optional Azure Monitor dependency in pyproject.toml to require opentelemetry-sdk instead of azure-monitor-events-extension.
• Removes azure-monitor-events-extension from samples/requirements.txt.

Testing improvements:

• Refactors tests in test_send_telemetry_appinsights.py to patch the new track_event function instead of the old event extension, and adds a helper to extract event properties from mock calls. [1] [2] [3] [4] [5] [6] [7]
• Adds a new test to verify that reserved log record attributes (like microsoft.custom_event.name) are handled safely and not overwritten.

Validation

• Ran quote-of-the-day-python sample locally. Changed the FeatureManagement-Python dependency to the local version using command:

pip install -e C:\Users\yuanqu\workplace\FeatureManagement-Python

Verified that quota-of-the-day app is still able to send telemetry to my testing app insights in the correct location.