- We recently deleted a load of old Homebrew/formula-patches patches for
  non-existent core formulae
  (https://github.com/Homebrew/formula-patches/pull/283). This is a good
  action to take. Users should always be able to retrieve the patch once
  it's been deleted from the repo, if the formula they continue to use
  specifies a git revision to pull from, not just `master`.
- The code to detect `master` formulae was already here, so this adds
  another GitHub host to the detection: `raw.githubusercontent.com` as
  that's what the current patches that use `master`
  (https://github.com/Homebrew/homebrew-core/pull/51329) link to.
- Fixes https://github.com/Homebrew/homebrew-core/issues/51313.

- Only try to call `.match?` on strings that aren't nil.

Make the filenames consistent with the class names.

Use 124 max line length everywhere. Also, reduce tap max line length to
189 as Homebrew/homebrew-core has that as a maximum now. In future
Homebrew/homebrew-core will also be reduced to 124 maximum line length.