Move RemoteImageBuffer methods from RemoteDisplayListRecorder to RemoteImageBuffer
<rdar://problem/114970484>
Pull request: https://github.com/WebKit/WebKit/pull/17427
Committed 267777@main (d9f5ea75d625): <https://commits.webkit.org/267777@main> Reviewed commits have been landed. Closing PR #17427 and removing active labels.