When clicking the edit icon of a subfolder in the file tree view of the filepicker the modal does not receive focus when it is opened. In addition you can't trigger the edit menu using the keyboard (only clicking works).

This is an issue for both boost and clean themes.

Steps to replicate:

1. Create a course
2. Add a folder resource to the course
3. View the resource and click "edit"
4. Change the view to the file tree (top right icon in the file picker)
5. Create a new folder in the file picker (second from left icon)
6. Click the little icon to edit the new folder you created (the weird little paper looking thing over the folder)
7. The modal will open without focus being set on it, meaning you can't hit the esc key to close it. You have to hit tab in order to give it focus.
8. Close the modal
9. Try to open the modal again using the keyboard. You should be able to navigate focus to the little edit icon using tab however hitting enter doesn't open the modal.