brew packages being installed even if they are already installed 🤔

[jessebot]

we should skip installing them if they're already there, because we already handle the upgrade edge case.

[jessebot]

this was happening for apt as well, and it was at least partially because apt list --installed returns output like this:

apt-config-icons/testing,testing,testing,testing,now 0.15.5-1 all [installed,automatic]

But we need it to be just the package name, so we're changing it to apt-cache pkgnames as of #94

[jessebot]

part of the issue was rich vs rich-cli. Some other weird package names vs install names I'm currently sorting through as well.

[jessebot]

ag vs the_silver_searcher 🤷

[jessebot]

this was also caused by package names like --cask iterm2 (for brew) and nvidia-driver-libs:i386 (for apt). I added in some fixes for that in the linked PR. Also did a minor refactor for future me to understand how this package install file even works

[jessebot]

I can't actually fix the steam:i386 error because we currently use apt-cache pkgnames to look for the packages, and steam doesn't show up there at all. It does show in apt list --installed but I don't feel like it realllly matters for now, because then I'd need another conditional just for steam, and that's getting a bit much.

This has been fixed and tested on both macOS and Linux though (or will be when the above PR is merged)