Implement proper no-claim mode support

In the no-claim mode should not depend on any artefacts of the initial snapshot after the restore. In order to do that we should pass a flag along with the RPC and later on with a CheckpointBarrier to notify TaskManagers about that intention. Moreover state backends should take the flag into consideration and take "full snapshots".

The flag should be passed until the first checkpoint succeeds

• RocksDB state backend should upload all files instead of reusing artefacts from the initial one

https://cwiki.apache.org/confluence/x/bIyqCw#FLIP193:Snapshotsownership-No-claimmode(defaultmode)