Add handling for Fuchsia tests

To accomplish this, the rebase script is migrated to use ResultDB.

Change-Id: I9799af2a3172b57d5ca83b01b196b75880fc414d
Bug: 40802670, b:40802670, b:323348541
Fixed: b:40802670, b:323348541
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5672490
Reviewed-by: Tzarial Kuznia <zork@chromium.org>
Reviewed-by: Mark Schillaci <mschillaci@google.com>
Commit-Queue: Jonny Wang <jonnywang@google.com>
Auto-Submit: Jonny Wang <jonnywang@google.com>
Cr-Commit-Position: refs/heads/main@{#1324216}