Imports Feature: Add valid paths dropdown & invalid path references warning

[Daniel-Faber]

Just tested the Imports Feature and seems like a really nice complementary feature to the Secrets Referencing Feature. What would be really nice to have, is a drop-down of all paths available in a given environment, so I can not set a path, that does not exist.
The other way around would be even more important though: Having a little warning sign, if I have imported a path / folder somewhere, that does not exist. Could be because I have a typo (--> path dropdown) or also because I deleted a folder and/or re-organised the structure. Just a little warning on the frontpage like "you have invalid import path references in [...]" would be really helpful.

Sidenote: The python SDK throws a very unspecific exception in this case just stating error decoding response body: missing field folderId