snapshotctl: Verify data blocks

1: Extract hash values from verity merkel tree
2: Verify data blocks with the merkel tree hash value

$snapshotctl dump-verity-hash /data/verity-hash/ -verify

verity hash value will be stored in the file for each partition

Bug: 371304627
Test: snapshotctl dump-verity-hash /data/verity-hash -verify
Change-Id: Ic93092422d0cec5d20c2177033a91e57e242fe3f
Signed-off-by: Akilesh Kailash <akailash@google.com>