FBCM-5217 [Bugfix] Disabled Typeahead Still Allows Changing Selection

[boygao1992]

What does this pull request do?

Before, when a single-value Typeahead is disabled, one can still change the selection by clicking on Change button to open the item container and then make a selection there. Fixed by not registering ToggleClick action on the Change button (a span styled as a button which doesn't support disabled prop) when the Typeahead is disabled.

How should this be manually tested?

• make
• open dist/index.html and go to Typeahead tab (#typeaheads)
• scroll down to Typeaheads - State Variants section, second example on the left, and click on the Change button
  • nothing should happen
  • you can check the broken behavior in current UI Guide for comparison

[davezuch]

Looks good! I might go one further and not have a link cursor when hovering disabled buttons, but maybe that's outside the scope of this fix.

[boygao1992]

Thanks for the review!