Add the display mode options to context menu and allow setting them on PDFDocumentLayout
<rdar://problem/119155634>
Pull request: https://github.com/WebKit/WebKit/pull/21304
Committed 271573@main (2a7a56ba875a): <https://commits.webkit.org/271573@main> Reviewed commits have been landed. Closing PR #21304 and removing active labels.