[New Feature]: Support stage-in from Unity DS

[LucaCinquini]

Currently the CWL modular DAG will only support staging in data from DAAC. The TROPESS use case requires querying the Unity DS to retrieve a STAC catalog that is used to stage-in.

The following steps were discussed during the meeting:
o Add a flag to the UI to indicate the stage in source: "Unity" or "DAAC" -> this will determine the Auth type
o Retrieve Unity credentials from SSM
o Pass all the parameters to the stage-in CWL, even if they are not going to be used

Repo containing the examples:

https://github.com/unity-sds/unity-data-services/tree/develop/cwl