[SR] Allow users to perform cleanup action for a repository

[jen-huang]

Describe the feature:
A new ES endpoint was added by elastic/elasticsearch#43900.
POST /_snapshot/{repository_name}/_cleanup will cleanup unreferenced data in the given repository.

Snapshot and Restore > Repositories should surface this action in the existing UI as a single action (on each repository row, and in its details, but not available as a bulk action when selecting multiple repositories).

[elasticmachine]

Pinging @elastic/es-ui

[jen-huang]

@original-brownbear, does this new endpoint support cleaning up multiple repositories at a time, or _all? Are there any negative consequences if the user sends this request in rapid succession? This will help us figure out if we should surface this in the UI as a "single" action or a "bulk" action (such as selecting multiple repositories in the table for deletion).

[original-brownbear]

@jen-huang

does this new endpoint support cleaning up multiple repositories at a time, or _all?

No, it only works on a single repository at a time.

Are there any negative consequences if the user sends this request in rapid succession?

Not really. But note that you can only run a single cleanup operation at a time, so if "rapid succession" means sending requests in parallel then you will get errors (exactly like those you get when trying to run snapshot create or delete in parallel).

[jen-huang]

Thanks @original-brownbear, I've updated the description to specify that it should be implemented in the UI as a single action (not available as a bulk action).

[cjcenizal]

Based on this behavior, we should also make sure the UI handles this error gracefully and surfaces it to the user in a way they can understand, e.g. a toast or callout stating, "Your previous cleanup is still in progress. Wait a few seconds and try again."