Abolish repository processes

https://redmine.teklia.com/issues/5720

Requires backend#1706 (closed)

• Remove the revision column from the process status page
• Remove the repos/listAvailable action, repos/setAvailable mutation, repos.available state, and listAvailableRepositories API helper, which have been gone since backend!2210 (merged) and are no longer used by any component or view
• Remove the repository mode from the process list filters
• The repository mode should no longer be listed in the frontend's config, enums, or TypeScript definitions
• Process.revision should no longer be defined in any TypeScript definition