ReverifyPiece() is not currently hooked up to anything, but is planned
to take the place of audit.(*Verifier).Reverify().
ReverifyPiece() works by downloading one piece in its entirety, rather
than pulling an entire stripe across many nodes.
Change-Id: Ie2c680f4d3c3b65273a72466a3f9f55c115b0311
This table will be used as a queue for pieces that need to be reverified
(a regular audit timed out on the owning node, so now that node is
contained and we need to validate the piece before un-containing it).
Refs: https://github.com/storj/storj/issues/5228
Change-Id: I5dcd26b6adced8674cbd81884c1543a61ea9d4c8