Converts characters to their unicode-escaped notations.
Supports the prefixes:
\u
%u
U+
e.g. σου
becomes \u03C3\u03BF\u03C5
Converts unicode-escaped character notation back into raw characters.
Supports the prefixes:
\u
%u
U+
e.g. \u03c3\u03bf\u03c5
becomes σου