This commit introduces the ability to configure the Azure Monitor Exporter using a connection string. The connection string simplifies the configuration by encapsulating various settings into a single string, making it easier for users to configure the exporter.

Changes:
- Update the Config struct to include a ConnectionString field.
- Modify the factory's getTransportChannel method to parse the connection string and apply the settings to the exporter configuration.
- Update the tests to cover the new connection string functionality.
- Update the documentation to provide examples of how to use the connection string for configuration.

By supporting connection strings, users now have a more straightforward way to configure the Azure Monitor Exporter, aligning with Azure Monitor's standard practices.

Refs: open-telemetry#28853 (Add ConnectionString Support for Azure Monitor Exporter)

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