Extension install confirm dialog options not updating correctly.

[acekyd]

Describe the bug

The confirm button states on the extension install modal isn't updated accordingly. The No button should probably be hidden when Processing a new install. Doesn't do anything when clicked though.

To Reproduce Steps to reproduce the behavior:

1. Try to install a new extension via direct link e.g from the directory
2. Click on 'Yes'

Expected behavior A clear state update showing that the install is processing.

Screenshots