Update on save instead of change

The role will now change on saving the form instead of on changing the
selected radio button.
Re-enable refreshing endpoints when deleting join instances
Don't try to create a UserRole with role_id == 0

* Previously, "No Access" role would do so
Move 'Save' text to template
Merge pull request #1466 from reciprocity/feature/update-program-role-on-modal-save

Update on save instead of change