Create a regression test for the database correctness

[MattF-NSIDC]

When NSIDC 0080 v2 was released and v1 deprecated, we lost the ability to recreate the database from v1 data. So we can't validate that with v2 data, we generate the exact same database.

It would be impractical to commit the database to the Git repo and use it for regression testing. We'd like a regression test based on hashing a subset of the database, e.g. up to 2022, and comparing it to a known-good hash.

We would need a known-good copy of the database permanently archived somewhere (and the unit test should print a link to it when it fails) to enable deeper investigation if the hash check ever does fail.