A bunch of random cleanups/fixes for TalkatuView and TalkatuInput

This still doesn't fix the input, but it fixes a number of other issues.

Testing Done:
Ran the demo

* verified the extra menu of `TalkatuInput` worked
* manually verified that the event controller callbacks were called
* manually verified that the notify callbacks were called.

Reviewed at https://reviews.imfreedom.org/r/1279/