[Media] Rename VideoFullscreenManager and friends to VideoPresentationManager*
<rdar://problem/116443401>
Pull request: https://github.com/WebKit/WebKit/pull/18609
Committed 268850@main (3611be9d6e54): <https://commits.webkit.org/268850@main> Reviewed commits have been landed. Closing PR #18609 and removing active labels.