Expose analytics enabled status in API

Problem
The /analytics/exports API endpoint returns a 400 error if any of the requested inboxes do not have analytics enabled. There is no way to check analytics enablement status in advance, making it difficult to manage analytics exports for large inbox lists without encountering errors.

Request
Provide an API field or endpoint to check whether analytics is enabled for specific inboxes, allowing developers to filter or handle inboxes appropriately before making analytics export requests.