Disconnected indicator list from models

[dgarijo]

Describe the bug
After the latest updates, the indicator list when setting a problem statement does not select many of the models listed there, despite each of those models having the useful_for_calculating_index property declared.
Example: HAND with the flooding_contour, MODFLOW, drought models, etc.

It looks like the changes to the standard variable URIs have affected this. The models that are linked through outputs seem to be recognized fine (e.g., Cycles).

[dgarijo]

Also, PIHM does not appear in the indicator list. It should appear for Streamflow duration index