This reverts commit d1b27019.

Reason for revert: Broke vtune build, tsan build and possibly others

Original change's description:
> [include] Split out v8.h
>
> This moves every single class/function out of include/v8.h into a
> separate header in include/, which v8.h then includes so that
> externally nothing appears to have changed.
>
> Every include of v8.h from inside v8 has been changed to a more
> fine-grained include.
>
> Previously inline functions defined at the bottom of v8.h would call
> private non-inline functions in the V8 class. Since that class is now
> in v8-initialization.h and is rarely included (as that would create
> dependency cycles), this is not possible and so those methods have been
> moved out of the V8 class into the namespace v8::api_internal.
>
> None of the previous files in include/ now #include v8.h, which means
> if embedders were relying on this transitive dependency then it will
> give compile failures.
>
> v8-inspector.h does depend on v8-scripts.h for the time being to ensure
> that Chrome continue to compile but that change will be reverted once
> those transitive #includes in chrome are changed to include it directly.
>
> Full design:
> https://docs.google.com/document/d/1rTD--I8hCAr-Rho1WTumZzFKaDpEp0IJ8ejZtk4nJdA/edit?usp=sharing
>
> Bug: v8:11965
> Change-Id: I53b84b29581632710edc80eb11f819c2097a2877
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3097448
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#76424}

Bug: v8:11965
Change-Id: Id57313ae992e720c8b19abc975cd69729e1344aa
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3113627
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Owners-Override: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76428}