Now that PartialSerializer/Deserializer/etc have been renamed to
ContextSerializer/ContextDeserializer/etc, the files can now be renamed
hopefully leaving the full history available in code search.

Bug: v8:10416
Change-Id: I266c915f6d01a7e2913c4d34d9913fa551046dc1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144061
Auto-Submit: Dan Elphick <delphick@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67333}