[url] Make path URL parsing more lax

Parsing the path component of a non-special URL like javascript or data
should not fail for invalid URL characters like \uFFFF. See this bit
in the spec:
https://url.spec.whatwg.org/#cannot-be-a-base-url-path-state

Note: some failing WPTs are added which are because url parsing
replaces invalid characters (e.g. \uFFFF) with the replacement char
\uFFFD, when that isn't in the spec.

Bug: 925614
Change-Id: I450495bfdfa68dc70334ebed16a3ecc0d5737e88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1551917
Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#648155}