Add kiki-mig environment to test db migrations

[pivotalgeorge]

the new kiki environment is set up like the old kiki environment (short-lived, cf-deployment-based, with the use-postgres ops file).

It is intended to ensure db migrations do not break CAPI during upgrade. see the capi-ci README

This changeset includes

• bbl up/down for kiki-mig
• back-compat job that bosh deletes and redeploys cf, runs migrations, and CATS and SITS test suites
• deprecated db ip caching code from apply_latest_migrations removed in afcc169 but relevant to this work
• add attempts: 5 to SITS run against kiki in back-compat
• gate bump-ci-passed on kiki passing migrations

Key followup work: issue https://github.com/cloudfoundry/capi-ci/issues/49

Co-authored-by: Seth Boyles seth.boyles@broadcom.com