fix: version 0 support and backfill from edit versions

Fix: Version 0 support and backfill from edit versions

Description

Currently our record history and versioning we are not creating a snapshot of version 0 and after an edit version 1 is being created with no snapshot of the initial version which is being lost. This this MR changes the validations to allow version 0 and 2 backfills:

1. Backfill through migration which creates version 0 for records which do not have any versions crated
2. Custom backfill script to reconstruct version 0 from version 1 meta-data

Checklist

• The bug has been reproduced and confirmed.
• A clear and concise fix has been implemented.
• New tests have been added to prevent regressions.
• Existing tests are passing.

Related Issue(s)

Closes #89 (closed)