Fix issue with parsers that return unicode characters in getCharacters()
Fix issue with parsers that return unicode characters in getCharacters()

thephpleague/commonmark,hason/commonmark,kkiernan/commonmark,colinodell/commonmark,postalservice14/commonmark,garethellis36/commonmark,postalservice14/commonmark,hason/commonmark,thephpleague/commonmark,kkiernan/commonmark,fesor/commonmark,garethellis36/commonmark,fesor/commonmark