Cleanup and reorganization

[CalebQ42]

This is a replacement of #249. This is only a couple parts of that PR and I'll probably re-base the rest in another PR down the road.

This is mostly some minor fixes suggested by linters along with a couple more major changes:

• Move files around to follow the official organization guide
• Replace depreciated openpgp library with one that's maintained
• Updated dependencies

[probonopd]

Sorry if I broke it with aa7e315. Didn't think of this side effect. My bad!

[CalebQ42]

No problem. I don't know why my attempt at fixing the conflict the first time didn't work, lol.