Set up test databases to support reprocessing existing MCS (and other) data

This has been implemented using foreign tables, where the real opdb is made read-only except for a handful of tables which can be written to in a different database: the real opdb cannot be modified, but it looks exactly like the real one to the actor, etc.

This requires the postgres extension postgres_fdw, which due to a versioning problem could not be installed on the summit during the run. So is installed in Hilo but accessible from the summit.

There are a few limitations on usage, but those are for other tickets.

The implementation is wrapped in two spt_operational_database scripts, one which must be run by a DB administrator, and the other simply by a pfs user. For example for a an MCS test database I'll name mcs_test_01: makeTestDb mcs_test_01 and configTestDb -t mcs_data,mcs_spi_transformation,cobra_match mcs_test_01. That last list of writable tables needs to grow, depending on the other tickets.