Replace (some of?) webapollo.py's interactions with Apollo, with new Galaxy feature

[hexylena]

Looking at galaxyproject/galaxy#17087 we can potentially replace some of the mechanism with this new feature, though I'm not sure how we'd handle system-level credentials like we have now where there's a single set of admin credentials for apollo, that's configured Galaxy-wide.

For the user-credentials in preferences configuration (which we never used because it was terrible UX) it would be possible to use this, though we'd lose the caching mechanism. I wonder if Galaxy ever fixed that bug where opening the tool interface once hit the api 3-4 times 🤔