Come up with a way to handle extended grapheme clusters

[MnO2]

Examples here: https://developer.apple.com/swift/blog/?id=30

"abcde\u{0301}\u{1100}\u{1161}\u{AC00}" should not be segmented as "abcde" and "\u{0301}\u{1100}\u{1161}\u{AC00}". "e\u{0301}" should be together.

[MnO2]

https://unicode-rs.github.io/unicode-segmentation/unicode_segmentation/struct.Graphemes.html This could be considered. But only required if the behaviour of re_han results into incorrect segmentation by SplitMatch