talkatu/talkatu

Update the attachment dialog for GTK4
gtk4
2022-01-16, Gary Kramlich
b6ad374a15c6
Update the attachment dialog for GTK4

Testing Done:
Compiled and verified that all warnings/errors were fixed in `talkatuattachmentdialog.c`

Reviewed at https://reviews.imfreedom.org/r/1234/
# 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
```