Add C++11-style raw string literals (R"delimiter(content)delimiter") to
ChaiScript. Raw strings do not process escape sequences or perform string
interpolation, solving the issue where base85 encoded data containing ${
sequences would trigger unwanted instring_eval. The implementation adds
Raw_String_() and Raw_String() parser functions and hooks them into the
expression parser.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
