[RealTimeReporting] Add WPT for real time reporting.
Only covers single seller in this CL. Will add some tests for component
auctions in a separate CL.
Bug: 337132755
Change-Id: I2a1a8e755f06dc310e4140359a77779801026d65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5914124
Commit-Queue: Qingxin Wu qingxinwu@google.com
Reviewed-by: Maks Orlovich morlovich@chromium.org
Cr-Commit-Position: refs/heads/main@{#1377815}