Cannot use image editor without publish permission

Description

If an editor does not have publish permission, they cannot save an image.

Steps to reproduce:
1. Login as a WebEditor user who does not have publish permission on a content folder.
2. On an image in that folder, click open in image editor.
3. Resize or crop the image and click save.
4. User sees error You do not have permission to perform this action.

Expected: You can edit the image even if you lack publish permission.
Actual: When they click save, users get "You do not have permission to perform this action". It doesn't matter if they choose Save as copy or Replace original, both options give the error.