Add WPTs for race-network-and-fetch-handler option

[chromium-wpt-export-bot]

Adds tests for race-network-and-fetch-handler, which is the service
worker static routing API's router source option.

This tests check the case when the network request wins and the fetch
handler wins the race respectively, both for the main resource and
subresource.

Bug: 1519727
Change-Id: I19fe304c294f64d99d08c76be113a41d726b8d52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5256919
Commit-Queue: Shunya Shishido <sisidovski@chromium.org>
Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1255046}

[wpt-pr-bot]

The review process for this patch is being conducted in the Chromium project.

[dev-ansung]

Unstable results

Test	Subtest	Results	Messages
/service-workers/service-worker/tentative/static-router/static-router-race-network-and-fetch-handler.https.html		OK: 9/10, TIMEOUT: 1/10
/service-workers/service-worker/tentative/static-router/static-router-race-network-and-fetch-handler.https.html	Main resource load matched the rule with race-network-and-fetch-handler source, and the server reseponse is faster than the fetch handler	FAIL: 9/10, TIMEOUT: 1/10	assert_unreached: unregister and register should not fail: ServiceWorker script at https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/static-router-race-network-and-fetch-handler-sw.js?key=condition-urlpattern-string-source-race-network-and-fetch-handler for scope https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/ threw an exception during script evaluation. Reached unreachable code;Test timed out
/service-workers/service-worker/tentative/static-router/static-router-race-network-and-fetch-handler.https.html	Subresource load matched the rule with race-network-and-fetch-handler source, and the fetch handler response is faster than the server response	FAIL: 9/10, NOTRUN: 1/10	assert_unreached: unregister and register should not fail: ServiceWorker script at https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/static-router-race-network-and-fetch-handler-sw.js?key=condition-urlpattern-string-source-race-network-and-fetch-handler for scope https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/ threw an exception during script evaluation. Reached unreachable code
/service-workers/service-worker/tentative/static-router/static-router-race-network-and-fetch-handler.https.html	Subresource load matched the rule with race-network-and-fetch-handler source, and the server reseponse is faster than the fetch handler	FAIL: 9/10, NOTRUN: 1/10	assert_unreached: unregister and register should not fail: ServiceWorker script at https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/static-router-race-network-and-fetch-handler-sw.js?key=condition-urlpattern-string-source-race-network-and-fetch-handler for scope https://web-platform.test:8443/service-workers/service-worker/tentative/static-router/resources/ threw an exception during script evaluation. Reached unreachable code

[dev-ansung]

Filed https://crbug.com/1524538.
@KyleJu @DanielRyanSmith Could you please admin merge? Thanks