Migrate to a File-Based Catalog

[komish]

As described here https://olm.operatorframework.io/docs/reference/file-based-catalogs/, this project currently uses database-backed catalogs and needs to transition to File-based catalogs.

[komish]

Couple of implementation notes from testing FBC:

• Seems like we can store the catalog in the repository.
• To migrate, opm (1.21.z) offers opm migrate E.g.

opm migrate --output yaml quay.io/opdev/simple-demo-operator-catalog:v0.0.6 catalog

• If a Containerfile is not generated, generate one with opm generate containerfile
• When adding a new bundle using render, you'll also have to edit the catalog.yaml for the operator to add the "replaces" entries. E.g.

opm render quay.io/opdev/simple-demo-operator-bundle:v0.0.6 --output=yaml >> catalog/simple-demo-operator/catalog.yaml

• building the catalog is now a docker build command away.
• Avoid using the opm index command because it appears to use the old sqlite format.

[tkrishtop]

Hi @komish, FYI we hit this issue already because we had to generate the index image on our own to support disconnected environments.
We had to use FBC for OCP >= 4.9 and the old format for OCP < 4.9.