Emitting acceptor errors terminates the really slow search for licenses

[WildCryptoFox]

cargo about generate stops looking for licenses after it finds a license which was not accepted. This is especially annoying when working with many files as the current iteration approach is really quite slow.

For comparison. ripgrep even with --no-ignore flies through all my files almost immediately. It would be worth taking a few pages out of rg's book.

Edit: cargo license does not do the deep analysis to find licenses but is immediate to give feedback.