Reorganize config.yaml

[davramov]

Originally posted by @kkamdin in #62 (comment)

As we add more beamline flows to this repo, we may want to reorganize config.yaml into a shared and beamlines structure. For example:

shared:
  scicat:
    base_url: ${SCICAT_URL:https://scicat.example}
  ghcr_images:
    repo: ghcr.io/als-computing
  hpss:
    alsdev_endpoint: ${HPSS_ALSDEV:alsdev#hpss}

beamlines:
  "8.3.2":
    globus:
      endpoints:
        spot832:
          uuid: "..."
          name: "spot832"
          uri: "spot832.lbl.gov"
          root_path: "/"
          ...

This way, when we initialize a specific BeamlineConfig, we can isolate just the endpoints or images that the beamline is configured to load.