* misra.py: Use standard string module * misra.py: Fixup R4.1 References: * https://trac.cppcheck.net/ticket/9370 * https://sourceforge.net/p/cppcheck/discussion/development/thread/7274ed3842/?limit=25#799a * Add more examples from @matzeschmid PR * Add more out-of-bounds tests * Fix R4.1. * Compress hex condition * Add more test cases * Fix python3 zip import