Built in DAM file attribution for Workshop maps.

For credits sake, would be nice for the DAM files uploaded to the workshop to carry the information of whoever made it. Maybe with some ability to bring it up as credits (similar to how the current version popup from the help menu works), when having a Workshop map is open.

This could also add second editors after the first in case someone reuploads a workshop map they downloaded and edited themselves.

Finally, could also tie the upload to the username, so maps become searchable by user and not just keywords.