Support `filesystem` catalog for local schemas

[jfallows]

Describe the desired outcome from the user's perspective
As DevOps, I want to be able to use the local filesystem for schemas provided by catalogs, making it easier to migrate to a remote catalog as needed.

Acceptance criteria

• support filesystem catalog resolving schemas relative to location of zilla.yaml

Additional context
This should let us simplify OptionsConfigAdapterSpi.adaptContext and remove ConfigAdapterContext for all bindings.