Backout the blueprint compiler stuff

Turns out we just got used to the GTK Builder ui format, so the blueprint
compiler doesn't really do much for us.

This was a backout of `8c78e806f7c7` but then I put bindings in for the toolbar, send button, and edited buttons.

Testing Done:
Built and ran the demo.

Reviewed at https://reviews.imfreedom.org/r/2213/