Problem/Motivation
We have no UI for editing/viewing/reverting custom block revisions.
Proposed resolution
Build apon #2350939: Implement a generic revision UI to add view history, revert revision, and delete revision functionality.
View revision functionality will not be added as viewing the latest Block Content entity is not supported.
Remaining tasks
Write patch✅Write tests✅- Reviews
User interface changes
New UI for viewing custom block revisions
API changes
New routes added.
New entity operations added for Block content.
New permissions added for each Block content type.