Consider updates to schemas when selecting records to evaluate for publication

[marksparkza]

The static data initialization script, which runs on deployment, updates schema timestamps if schema content has changed since the last deployment.

When publishing, a record should be selected for evaluation if its metadata schema - or any of its tags' schemas - has been updated since it was last evaluated.

[marksparkza]

This is only needed for records belonging to harvested collections, since only curator QC (and not metadata validity) applies to the publishing of non-harvested records.

There should still, however, be some means of invalidating previously validated records - though that should be captured as a separate issue.

There is also not really any point in checking tag schema timestamps. Tag instances must be valid when they are set on a record. If a tag schema changes subsequently, then a larger migration is probably needed.