Relocate deviceinfo to /usr/share

FINALLY!! @craftyguy 💛

Depends !4169 (merged)

Fixes #1836 (closed)

Fixes #2228 (closed)

TODO:

• Test
• Review other projects
  • boot-deploy 0.9
  • mkinitfs 2.1?
  • pmaports: !4037 (merged), !4129 (merged)
  • pmboostrap?
  • Others?
• Improve the messaging from the /etc/deviceinfo file
• Add constraints for boot-deploy, mkinitfs, devicepkg-dev and devicepkg-utils.
• Merge !4169 (merged)
• Make a blogpost! Might break some user scripts and users that modified the deviceinfo should at some point migrate. https://gitlab.com/postmarketOS/postmarketos.org/-/merge_requests/226

Basically, every deviceinfo user should be updated after the migration. I cannot think of anything else, but there are things that I might have missed that use deviceinfo. Any ideas?

Also, everything should still be reading /etc/deviceinfo, so this should have backwards compatibility, even though users won't get updates if the don't migrate.