This fixes some tests which expect "refs local" and "repo gc" outputs to match
the CIDs produced when adding data. These operations are now outputting CIDv1-raw
hashes, regardless of the original CIDs used to address those blocks, so some tests
fail.
The fix is usually:
* To use "block stat" to check if a block was correctly gc'ed
* To convert the CIDs to multihash (using cid-fmt) and compare those instead
4ac3ed3ebd