Support `link: :overwrite` option

[yelsa]

• set link: :overwrite per formula
• uses brew link --overwrite to force linking and overwrite all conflicting files
• use the linked? and keg_only? predicates available from Formula
• --force should only be passed when it's keg-only
• check linked/unlinked state to avoid re-calling brew link / brew unlink

Closes https://github.com/Homebrew/homebrew-bundle/issues/1062 Resolves https://github.com/Homebrew/homebrew-bundle/pull/1116#discussion_r975223823, https://github.com/Homebrew/homebrew-bundle/pull/1116#discussion_r976260667

[shanesmith]

This has unfortunately broken file path formulas: https://github.com/Homebrew/homebrew-bundle/issues/1460

As mentioned in the issue I've noticed file path formulas are essentially deprecated so not sure if it's worth a revert or an attempt to fix forward.