Add Super admin routes for user and orga management

[frcroth]

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• Create a new organization via POST api/organizations with sample2 user (This allows you to specify an existing user as admin) / use /auth/createOrganizationWithAdmin (This creates a new user as admin)
• Add user sample to this organization via POST api/organizations/:name/addUser
• Create a new user in this organization via POST auth/createUserInOrganization/:name
• Validate that all of this only works for super users.

Issues:

• fixes Super admin routes for user and orga management #7148

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(Please delete unneeded items, merge only when none are left open)

• Updated changelog
• Considered common edge cases

[fm3]

Thanks for having a look at this!

I think your version works well, but it could be simplified and be made more feature-complete by reusing some of the existing methods used during user signup/organization switching. I added some comments pointing to those.

Maybe you could have a look at that? Feel free to reorganize some of those, if it makes things easier, none of this is set in stone :)

We might even alter the existing routes (of course then we would have to adapt the frontend).

[fm3]

Almost there :)

[fm3]

🎉