Better function names @ utf8
Add function prototypes to get first & last char @ utf8
strToBgStr -> strToBgstr
strToBgStr -> strToBgstr @ test
Add testStringCopy
Implement bgstrAssign & bgstrCopy
Correct function name strToBgstr
Add testInsertChar
Correct bgcharLen signature
Correct bgstrCopy signature and add for helpers to count number of bytes
Suspend some tests, focus on counting bytes
Add test to count bytes in a bgstr
Remove redundant code
Fix function signatures
Implement functions to count bytes
Add testPositionToNthByte
Better test & function name
More test
Implement bgNthBgcharToNthByte
Correct testStringCopy