Establish entry points for accessing subsets of cached data

[phargogh]

#1 and #2 both deal with scripts to download, cache and process datasets for later use, with an implicit assumption that we will have a single data storage location for these that everyone can access. In reality, we will need to make this reasonably easy to do. Some ideas that have come up so far include:

Data hosting:

• Store on Oak and share with globus or SMB
• Store on GCP and share data via URLs (auth TBD)

Data subsetting:

• run a local script with your AOI and have files copied/subsetted for you
• access a cloud-hosted webapp to submit a job and then download the files

The result needs to be easy to use, but also needs to adhere to the licenses of the data products were serving and/or deriving other products from.