"Escape String Literal as UTF-8" creates illegal code

In C/C++ a \x escape sequence is "unbounded" (unlike other programming languages).

"\x123456" isn't "\x12" followed by "3456", it's the character 0x123456 (which likely is out of range).

This causes a bug with the UTF-8 quickfix:

    const QString str = "à123"; 

Get quick fixed to

    const QString str = "\xc3\xa0123"; 

Which is illegal/wrong.

It should be instead

 const QString str = "\xc3\xa0""123";