Returns a glyph-id with public identifier string.
 glyph-identifier = afii-glyph-identifier
 afii-glyph-identifier = #Adigit-10+
An afii-glyph-identifier is a single token; therefore, no whitespace
is allowed between the #A and the digits.
An afii-glyph-identifier represents the glyph-id returned by
(glyph-id "ISO/IEC 10036/RA//Glyphs::n")
where n is the same sequence of digits occurring in the
afii-glyph-identifier with leading zeros removed. The
value represented by the digits shall be between 1 and 232-1.