Update Emoji support to unicode 13.1, support all RGI emoji.

This now enables all RGI emoji (“recommended for general interchange”). This includes all those genderswapped and skin tone adjusted emoji, as well as some emoji that are done using a ZWJ sequence.

This MR switches the base file to emoji-test.txt, which is another unicode emoji file that includes a list of all RGI emoji and is easier to parse.