Refactor Project Api

[jochenklar]

This PR adds a subquery for highest role in the hierarchy and refactors ProjectSerializer to include the label of current_role and highest_role and adds project information for the latter, e.g.:

"current_role": {
    "role": "guest",
    "role_display": "Gast"
},
"highest_role": {
    "role": "owner",
    "role_display": "Besitzer",
    "project_id": 2,
    "project_title": "Parent"
},

[jochenklar]

Hi @CalamityC, I added a few more changes after our meeting:

• Filtering with ?role=owner should work now and returns the project when the current_role OR the highest_role is e.g. owner
• Ordering current_role or highest_role should work now. role does the same as highest_role, since the current project is included in highest_role
• There was a but in the subquery magic which should be fixed now.
• I removed owner, manager, etc. and snapshots from the Project API, since you fetch the Memberships and Snapshots seperately anyway, hope thats ok.
• I added ancestors to the general ProjectSerializer so that it should also be returned when posting.
• I added more caching so that the Project Request now much fewer database hits.

[jochenklar]

parent_title is back in the API!

[CalamityC]

I think we need that too, or how do we get the owner of a project in projects list (it's supposed to be displayed in the table)?

ATM we use it here:

rdmo/rdmo/projects/assets/js/projects/components/Main.js

Line 190 in 6a8aa38

{row.owners.map(owner => owner.full_name).join('; ')}

[jochenklar]

Yes, I forgot about this. I added them again. But now with more database magic ✨