chore(manager): implement a logic to remove junk sent over p2p for Data part in DataStoreRetrieveLoop

[gupadhyaya]

in DataStoreRetrieveLoop there is no immediate rejection logic for any junk sent over the p2p for Data. the p2p validate checks for lastDataHash, but this can easily be incorporated in the junk.

ideal test would be check that the data hash is part of some SignedHeader which is p2p gossiped.

this kind of early junk detection is needed, similar to HeaderStoreRetrieveLoop which removes junk by checking the signed signature.