Split out IPC EnumTraits and Persistence EnumTraits so we can start porting the IPC usages to the new serialization format
Pull request: https://github.com/WebKit/WebKit/pull/7329
<rdar://problem/103120664>
Committed 257729@main (e865417a3903): <https://commits.webkit.org/257729@main> Reviewed commits have been landed. Closing PR #7329 and removing active labels.