Databases are no longer directly accessible, and each environment may have connections to ID3C configured differently, so replacing hard coded URIs with placeholders. `sqitch.template.conf` should be copied to `sqitch.conf` and the database connection URIs should updated in that file prior to running sqitch commands.

Implementing project-specific row-level security with newly added role and related constraint on sample table.

Adds trigger functions to ensure that row-level security for sequencing data matches the security in place on the corresponding sample record.

The `access_role` value is initially set on the sample record (enforced with a check constraint) and then must match across related sequencing records (enforced with these trigger functions).