talkatu/talkatu

A bunch of random cleanups/fixes for TalkatuView and TalkatuInput
gtk4
2022-02-02, Gary Kramlich
68f23f6ebc61
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/
# Building
Talkatu uses [meson](https://mesonbuild.com) as it's build system.
Meson requires you to build in a directory other than the source directory.
To compile you can use the following commands:
```
meson build
cd build
ninja install
```