**Fixes**
- Fixed decoding of escape sequences in quoted name selectors and string literals. We now raise a `JSONPathSyntaxError` for invalid code points.
- Fixed parsing of number literals with an exponent. We now allow 'e' to be upper case.
- Fixed handling of trailing commas in bracketed segments. We now raise a `JSONPathSyntaxError` in such cases.
- Fixed handling of invalid number literals. We now raise a syntax error for invalid leading zeros and extra negative signs.