Emoji sequences in the grapheme segmentation spec are a bit tricky:
\p{Extended_Pictographic} Extend* ZWJ × \p{Extended_Pictographic}
Our current strategy of tracking a boolean to indicate if we are in an
emoji sequence was causing us to break up emoji made of multiple sub-
sequences. For example, in the "family: man, woman, girl, boy" sequence:
U+1F468 U+200D U+1F469 U+200D U+1F467 U+200D U+1F466
We would break at indices 0 (correctly) and 6 (incorrectly).
Instead of tracking a boolean, it's quite a bit simpler to reason about
emoji sequences by just skipping past them entirely. Note that in cases
like the above emoji, we skip one sub-sequence at a time.
For example the words "can't" and "32.3" should not have boundaries
detected on the "'" and "." code points, respectively.
The String test cases fixed here are because "b'ar" is now considered
one word.
Similar to commit 6d710eeb43. Rather than
pick-and-chosing what to support, let's just support all encodings now,
as it is trivial. For example, LibGUI will want the UTF-32 overloads.
