XForm update button should give feedback on click

[spwoodcock]

Describe the bug

• The XForm editing submit button does nothing visually when pressed.
• It calls the endpoint / submits the form, but provides no feedback to the user it was clicked.

To Reproduce

Try to upload a new form to a project.

Expected behavior

• The button should be disabled when clicked as visual feedback it was clicked.
• When the response returns success/fail, the button should be enabled again.
• Perhaps there should be a loading spinner while we wait for the endpoint to return too?