Fixed pause button not working

[sofian]

Summary

VideoImpl::setPlayState() wasn't declared virtual. VideoPlayerImpl declares its own setPlayState() that does the real work (_player->pause()/_player->play()), but since the base wasn't virtual it was just a separate function hiding the base one — never reachable through the VideoImpl* pointer that Video::_doPause()/_doPlay() actually call through. So pausing silently no-opped (just set a bookkeeping flag), while play appeared to work because VideoPlayerImpl::loadMovie() calls _player->play() directly on load, independent of this path.

Fix: made VideoImpl::setPlayState() virtual and added override on VideoPlayerImpl's.

Test plan

• qmake6 mapmap.pro && make builds clean
• tests/ suite builds and all 44 existing Qt Test cases pass
• Standalone dispatch test: calling setPlayState() through a VideoImpl* base pointer on a VideoPlayerImpl with no movie loaded returns true (dispatched to the base no-op) before the fix, and false (dispatched to the real derived implementation) after — confirmed both ways