[white-space] Turn `white-space` to a shorthand

This patch turns the `white-space` property to a shorthand
under a runtime switch `CSSWhiteSpaceShorthand`.

The parser and serializer in this CL supports the spec change
committed on 1st March, 2023[1], which addressed the
multi-value syntax request[2].

This patch also adds:
* The `white-space-collapse` property.
* The `nowrap` value to the `text-wrap` property.
to map all the existing `white-space` values.

The switch is currently off, because enabling it causes
several test failures in DOM, editing, copy/paste,
accessibility, and more, but when it's turned on, CSS parsing
tests added in this CL should pass. The plan is to fix these
failures in following CLs. When all tests and additional tests
for editing/etc. are all fixed, we can turn the switch on.

The `EWhiteSpace` enum is changed to bit-flags of the
longhands (`white-space-collapse` and `text-wrap`.) See
`white_spae.h`.

Regarding the storage in the `ComputedStyleBase`, having both
storage (for when the flag is on and off) is a waste, both
from memory and from read/write code performance point of view,
so the longhands storage is used even when the flag is off by
customized `ComputedStyle` functions; i.e., the storage for
the longhand version of the `white-space` is no longer used.
But this CL still preserves 1 bit for the `white-space` to
avoid changing the generator only for this transition period.

[1] https://github.com/w3c/csswg-drafts/pull/8274
[2] https://github.com/w3c/csswg-drafts/issues/5382

Bug: 1417543
Change-Id: I47080d0f10a4a5f366e3d855acfa5e584c029595
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4232738


Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1123192}