The logic for `cleanupInProgress()` was backwards everywhere (method itself and
all but one user). Also, we weren't checking it when removing a repository.
This lead to a bug (in the one spot that didn't use the method backwards) that prevented
the cleanup cluster state entry from ever being removed from the cluster state if master
failed over during the cleanup process.
This change corrects the backwards logic, adds a test that makes sure the cleanup
is always removed and adds a check that prevents repository removal during cleanup
to the repositories service.
Also, the failure handling logic in the cleanup action was broken. Repeated invocation would lead to the cleanup being removed from the cluster state even if it was in progress. Fixed by adding a flag that indicates whether or not any removal of the cleanup task from the cluster state must be executed. Sorry for mixing this in here, but I had to fix it in the same PR, as the first test (for master-failover) otherwise would often just delete the blocked cleanup action as a result of a transport master action retry.
25cc8e3663