create a directive to show busy states on buttons

[samrichardsontylertech]

Describe the feature:
A directive should be created to disable and show a progress indicator on a button when the associated action is in progress.

Describe any alternatives you've considered:

1. The associated action can be throttled via code. This works for quick actions run locally, but for longer ones like HTTP requests there isn't enough feedback for the user.
2. The button can just be disabled. Good for communicating that the action is unavailable, but it's ambiguous to the user why.
3. A progress indicator can be manually applied to the button. Feasible, but doing it correctly can be verbose, complicated, and prone to inconsistency and bugs. There are considerations like accessibility and maintaining a fixed size that might be overlooked.