[Cocoa] Add UnrealizedCoreTextFont to make it easier to make CTFontDescriptor and CTFont transformations more deliberate
<rdar://problem/105378692>
Pull request: https://github.com/WebKit/WebKit/pull/10015
Committed 260208@main (7dff0d1ab2dd): <https://commits.webkit.org/260208@main> Reviewed commits have been landed. Closing PR #10015 and removing active labels.