Set x-ms-app HTTP request header in Monitor Query library

[scottaddie]

Library name

azure-monitor-query

Please describe the feature.

The Azure Monitor Log Analytics service team stores the caller information for their REST APIs. To support tracking HTTP requests from the Azure Monitor Query library, send an x-ms-app request header. The header's value should be set to AzureMonitorQuerySDK. The metrics team uses the user agent to identify the caller. Send this header ONLY for logs queries.

[scottaddie]

After reviewing with the arch board, a decision was made to not make this change. As a workaround, the Draft service team can run a contains operation on the user agent string to identify the caller. This workaround has been communicated to Dan Hadari.