Allow BR restore schema into existing cluster without needing to remove CDC feed (pause only)

[bolt-leandro]

Feature Request

Is your feature request related to a problem? Please describe:
Migrating a schema from one TiDB to another needs a copy of data in target cluster.
Target TiDB cluster has existing CDC changefeeds.

Would like to use existing BR backups rather then making new logical dump/load restore process (which is also slower).
When trying BR restore, received the message below:

Error: failed to check task exists: found CDC changefeed(s): cluster/namespace: default/default changefeed(s): [changefeed-name], please stop changefeed(s) before restore

Pausing and resuming the changefeed doesn't work.

If you have tens/hundreds of CDC feeds, needing to remove and add all of them is extra operational overhead.
If CDC management for some feeds is with a different team, coordination, approval and other red tape is needed.

Describe the feature you'd like:
Allow BR restore into cluster with CDC changefeeds by pausing and resuming feeds.

Describe alternatives you've considered:
Use different restore method (eg: dumpling/lightning)

Teachability, Documentation, Adoption, Migration Strategy:
Running v7.1.3

[dveeden]

Related: #50738

[bolt-leandro]

Looks like this has been fixed. Tests against 8.5.1 showed it is now possible to restore a physical backup on a cluster that has CDC changefeeds running.