Check wK write permission before organization creation

[youri-k]

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• create an organization when the datastore doesn't has write permission => should not work
• create an organization when the datastore has write permission => should still work

Issues:

• fixes if organization creation fails (due to no write permission in binaryData), user is stuck #4455

---

• Updated changelog
• [ ] Updated migration guide if applicable
• [ ] Updated documentation if applicable
• [ ] Adapted wk-connect if datastore API changes
• Needs datastore update after deployment
• Ready for review

[youri-k]

I went with checking the write permission beforehand and leaving the folder creation at the end because otherwise the folder creation would be done without authentication.

[fm3]

Good thinking concerning the authentication :) I left a comment about the error messages. With that done this should be good to go!