terminal: glyph protocol parser and response encoder

This adds the core parse/encode for the still in-development and experimental
terminal glyph protocol: https://github.com/raphamorim/rio/pull/1542
Up to version 1.9.

The only cross-cutting change necessary was changing the APC
identification logic which previously only looked at a single byte to
support multi-byte identifiers since the glyph protocol uses `25a1`.

src/termio/stream_handler.zig

@@ -559,6 +559,8 @@ pub const StreamHandler = struct {
                     }
                 }
             },
+
+            .glyph => {},
         }
     }