IssueTracker

See design doc.

Compose's text system should keep a refcount of how many things currently want the keyboard to be open. It should provide a method to "sync" its state (whether it thinks the keyboard should be open) with the system. Any time the refcount changes, it should trigger a sync.

Properties:

• The keyboard will automatically be shown when something starts requesting it.
• The keyboard will automatically be hidden when all items requesting it stop requesting.
• User can close the keyboard at any time.
• Any component that wants to re-show the keyboard on interaction (e.g. when a TextField is tapped) can manually request a sync.