Switch staging hub on openscapes hub to its own EFS

[yuvipanda]

As part of #4453, we want to support running one EFS per hub. This allows accurate cost allocation per hub for home directory storage.

This task requires:

• Modify our terraform code to allow creation of multiple EFS instances (taking care to not damage the existing ones). Equivalent work done on GCP in Support creating multiple Filestore instances via Terraform on GCP #4334. Configure aws terraform to allow multiple efs #4498
• Setup an EFS instance for staging. The existing EFS can be retained for prod (and temporarily, workshop) Add a filestore for the staging hub of openscapes #4503
• Move the staging hub to use the new EFS instance set up for it. Existing data for the staging hub does not need to be migrated, and can be deleted.

Definition of done

The staging hub uses a new EFS instance set up specifically for it.

[GeorgianaElena]

I have finished the tasks of this issue. Only remaining bit is deleting the previous contents of the staging homedir. Will do so in a later iteration, after doing a workshop migration so I can still use it for testing.

Note

This task was a bit more complex than initially anticipated and required more effort than planned (first sub-task).
This was mostly due to the implementation details not being very similar with the GCP one because of differences in how we manage filestores on each cloud provider and required pivoting away from the terraform state mv approach to avoid running into unwanted issues having to run the command 5 times for each aws cluster.

Not sure what to do with this info, but leaving it here for reference.