isMD5 function
Checks if the string is a valid MD5 hash.
An MD5 hash is a 32-character hexadecimal string.
Example:
isMD5('d41d8cd98f00b204e9800998ecf8427e'); // true
isMD5('d41d8cd98f00b204e9800998ecf8427'); // false (too short)
Implementation
bool isMD5(String str) => _isMD5(str);