Consistent pkgver in device packages

Currently a mess, it's not consistent. Some increment pkgver by one, others by 0.1.. There's no policy about that, would be nice to have one. Either increment pkgver by one, or by 0.1. IMO I don't really care, as long as it's consistent.

Edit: TODO:

• Update pmbootstrap newapkbuild command to generate a pkgver=1 instead of pkgver=0.1
• Document it in the wiki: https://wiki.postmarketos.org/wiki/Packaging#device_packages_and_other_packages_without_sources (diff https://wiki.postmarketos.org/index.php?title=Packaging&type=revision&diff=58033&oldid=57887)
• Add CI that at least checks that all pkgvers are integers.
  • !4994 (closed)
• Update existing device packages
  • !4994 (closed)
• (Optional) Add CI that check "if checksums change, update pkgver, else pkgrel". Should be possible to disable for the cases were there is a legit use-case.

Cc: @pabloyoyoista