Throw Exception instead "return;"

Please, change this comment to real exception
https://github.com/mark-gerarts/automapper-plus/blob/d5ca462e99deae8c6628d15d5c67ab479ad1b8b9/src/MappingOperation/DefaultMappingOperation.php#L49
When this library is one block of big system, bugs like this is hard detection, if here will be real exception, life will be better, i think

Start with src/MappingOperation/DefaultMappingOperation.php at the linked line and read the surrounding comment and return statement to understand the unhandled condition. Replace the silent return with an exception as requested, then run the repository's relevant tests to confirm the failure is surfaced without breaking existing mappings.

Written by the indexing model from the issue text.