FRED and qtFRED quality-of-life improvements for highlighted models#7299

Goober5000 wants to merge 1 commit intoscp-fs2open:masterscp-fs2open/fs2open.github.com:masterfrom

Goober5000:fix/fred_subsys_bboxGoober5000/fs2open.github.com:fix/fred_subsys_bboxCopy head branch name to clipboard