Collaborators: Safe Area guidelines are not respected

On Collaborators screen "Add a new collaborator" row doesn't respect safe area guidelines.

### Expected
Safe area guidelines are respected.

### Observed
Safe area guidelines are not respected.

### Reproduced (on an iPhone with a notch)
1. Open a note
2. Open Options screen
3. Open Collaborators screen
4. Rotate into landscape
4. Observe that "Add a new collaborator" row doesn't respect safe area guidelines

Reproduce the issue on an iPhone with a notch by opening a note, navigating through Options to Collaborators, and rotating to landscape. Locate the Collaborators screen and inspect the “Add a new collaborator” row; done means the row respects the safe area in landscape.

Written by the indexing model from the issue text.