Cleanup UI resources

[iinuwa]

Converts to Blueprint templates and removes unnecessary menu.

[iinuwa]

Oh, boy. Getting blueprint-compiler to work properly in CI was a hassle.

• If I added as a meson subproject wrap, as the official docs say, somehow the blueprint-compiler tests ran in our test suite, even though they never appeared locally. 🤷
• I couldn't easily meson install, even if I set the prefix to ~/.local.
• I wound up packing the Python source into a zipapp and copying that to the path in order to make it work.

If there was a better way to avoid these problems, then please let me know!