Rewrite brew install completion to be entirely local
Rewrite brew install completion to be entirely local

This improves the speed of loading package/cask completions
by roughly an order of magnitude for the `brew install` and
`brew cask install` commands. It also improves reliability
as the rewrite eliminates dependence on `brew search`, which
takes additional time to execute because it searches through
all official taps.

caleb531/dotfiles,caleb531/dotfiles,caleb531/dotfiles,caleb531/dotfiles