Add crash keys to investigate GetServiceWorkerData crashes

This CL adds two crash keys that may be related to the crash in
crbug.com/389971360.

In crbug.com/389971360, it looks the crash is caused by the nullptr
access to `service_worker_data`. This could potentially happen when
`WillEvaluateServiceWorkerOnWorkerThread` is returned early in some
conditions. So this CL adds an enum class and member variable to keep
those cases, and add a crash key to be reported when the crash happened.

This CL also adds ServiceWorkerStartStatus in the caller side. This is
not cared in `DidStartServiceWorkerContextOnWorkerThread` at all, but
maybe we should handle it there.

Bug: 389971360
Change-Id: I2a00cf85ac758f63f0e6bae5fe226d07a8d1ae90
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6171946
Reviewed-by: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Devlin Cronin <rdevlin.cronin@chromium.org>
Commit-Queue: Shunya Shishido <sisidovski@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1412090}