Reland "Add WPT for Compression Dictionary Transport"

This reverts commit f27cfea7.

Reason for revert: Relanding dictionary-fetch-with-link-* tests.

dictionary-fetch-with-link-* tests are testing the behaviour of fetching
a dictionary using link elements or link HTTP header.
Fetching a dictionary is internally using requestIdleCallback in
blink::PreloadHelper::FetchDictionaryIfNeeded(). But requestIdleCallback
doesn't work correctly in the single-threaded compositor mode.
So this CL updates VirtualTestSuites for these tests to skip that mode
but expect to pass for virtual/threaded.

Also this CL make tests wait for a while with requestIdleCallback() to
ensure that the dictionary is fetched.


Original change's description:
> Revert "Add WPT for Compression Dictionary Transport"
>
> This partially reverts commit f8d14034.
>
> Reason for revert: dictionary-fetch-with-link-* tests are flaky.
> First failing run
> https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20Tests%20(dbg)(1)/119589/blamelist
>
> Original change's description:
> > Add WPT for Compression Dictionary Transport
> >
> > Bug: 1413922
> > Change-Id: I4f7aad71a043354f5c107a301b66d58a1409ef89
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5401505


> > Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
> > Reviewed-by: Patrick Meenan <pmeenan@chromium.org>
> > Cr-Commit-Position: refs/heads/main@{#1281548}
>
> Bug: 1413922
> Change-Id: If52e3f9074e51265da65fef08456fc1d42be735a
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5418514


> Reviewed-by: Fergal Daly <fergal@chromium.org>
> Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Cr-Commit-Position: refs/heads/main@{#1281675}

Bug: 1413922
Change-Id: Ie0ac767ff7626c6e2b2811e8631823204a590f8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5417959


Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Reviewed-by: Patrick Meenan <pmeenan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1282208}