Make ligo-raven compatible with GraceDB REST API and SDK simulateneously

Due to direction from the emfollow chairs, we will use the Gracedb SDK client at least for the beginning of O4, possibly reverting back to the standard REST API afterwards or into O5. Therefore, there is a need to give compatibility to both versions, controlling which API calls under the hood so no changes appear for users. This means we will need some way to distinguish whether the given GraceDB client is SDK or not.

We should create some tests to check whether we can call either client, but we can keep most tests as is.