[results.html] Support ResultDB

If ?json=<full_results_jsonp.js URL>&build_id=<build_bucket_id> is
specified in the results.html URL, we'll load full_results_jsonp.js
from the specified location (instead of from the same directory), and
fetch test artifact URLs from ResultDB. On startup, we'll fetch all
artifacts for tests with unexpected failures in batches asynchronously
and cache the result. If a test is expanded before the cache is ready or
the test is not included in the cache (e.g. the test didn't fail
unexpectedly), we'll fetch artifact URLs for the test with a dedicated
asynchronous request.

If there is only ?json=<full_results_jsonp.js URL> without build_id,
we'll load the specified full_results_jsonp.js and set the base URL
to the directory, assuming all artifacts are under the same directory.

Rebaseline script won't work in the ResultDB mode. We have added a
warning, and will probably remove the feature after we fully switch to
ResultDB.

To test, you can open the following URL:
.../results.html?json=https://chromium-layout-test-archives.storage.googleapis.com/mac10_13-blink-rel/18068/blink_web_tests%20%28with%20patch%29/full_results_jsonp.js&build_id=8796098237407454705

Bug: 1382949
Change-Id: Ibed27f7e83ff8f5bdb239ee1958d8ad396dc5314
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4068051
Reviewed-by: Weizhong Xia <weizhong@google.com>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1077834}