Updating quota for workspace shared storage

[TonyWildish-BH]

It would be really useful to be able to update the quota from within the TRE, if possible. We've already had two workspaces run out of space, and they started with 500 GB apiece.

Currently, the workspace storage quota is marked as non updatable in the workspace templates. However, Azure will quite happily let me go into the portal and change the quota, up or down. Is there a reason the template won't let me do that, such as terraform then doing a destroy/create instead of an update?