Semantic Kompakkt bugs

### SK Bugs
During user testing interviews I encountered some bugs on semantic Kompakkt.
I know that there are some changes in PRs and maybe then everything is solved, but I still wanted to document the bugs here for comparison and in case that something is missing

**Upload - Metadata:**

- Creator is still labelled as mandatory, but we changed it, that Contact person is mandatory and Creator is optional
- The input fields for "External Link" are immediately red, that's confusing for the user, since it is only optional and nothing is wrong yet. Can we change it that the fields only turn red, when there is an invalid input?

**Rights:**
- The Editor cannot edit or add any annotations to an object right now
- Transfer ownership is working. As a new owner I can do everything with the object on the object detail page, but in my profile it is restricted (see screenshot)

**3D-Settings:**
- when editing the background and then resetting it, it is not really the background that was set as default

**Object detail page:**
- The Link of "Related object structure" in the Metadata to Wikibase is not working