Add: abs databases from before v2.13.4

[nichwall]

This PR adds test databases for each ABS server version to test/server/testdata, using the naming scheme of schema_v[version].sql. These databases were created by:

• Checking out each release beginning with 2.3.0 and ensuring the correct version of node was used (node 16 prior to v2.8.0, node 20 afterwards)
• Deleting the 'config/` directory to ensure we started from a clean state
• Starting the server
• Running sqlite3 config/absdatabase.sqlite ".schema" > "schema_v[version].sql"

This inspiration was taken from comments in the PR about series migrations, specifically #3417 (comment). A different directory could be used for these databases, but I didn't have a better suggestion than was mentioned there.

We don't really need every database beginning with 2.3.0, but am including them all for completeness.

Follow-up

Would it be useful to have a GH workflow which can be manually triggered (probably after the version bump commit, but before release?) to run the sqlite dump command and open a PR with the new SQL file? This would be merged manually, but then is a button press instead of needing to remember to clean out config/, start the server, and move/rename the file.

If so, I will do that in a separate PR.