- factor out bitsPerByte constant
- panic if the necessary args aren't passed to GetStorageValueMetadataForPackedSlot
- only have one decode integer method in the deocoder file
- If processing a new diff for a row that already exists in the DB,
ignore the error without logging or queueing
- If processing a queued diff for a row that already exists, remove
it from the queue
libraries/shared; adjust omni test_helpers to drop and recreate
checked_headers table to avoid reaching 1600 column limit after repeated
tests (dropping columns doesn't actually remove them from contributing
to that limit)