Allow Mirror Database to use Variable Library, not just Deployment Rules

Currently, the source connection for Mirrored DBs is managed through Deployment Rules in data pipelines.

There is no way to use Variable Libraries with Mirrored DB, like you can do in CopyJob or Data Pipelines.

Idea: Allow Mirrored DB to use variable library to parameterize connection ID.

My team plans to use fabric ci-cd instead of Fabric Deployment pipelines, so we cannot use Deployment Rules in Fabric deployment pipelines.

What we can do is, parameterize the connection ID in GitHub yml file and update on deployment to workspaces.

However, we use Variable Library for CopyJob and Data Pipeline. It would be nice to use Variable Library across the any Fabric ingestion item.