Add `ECMAScriptRegex`, LibRegex's C++ facade for ECMAScript regexes.
The facade owns compilation, execution, captures, named groups, and
error translation for the Rust backend, which lets callers stop
depending on the legacy parser and matcher types directly. Use it in the
remaining non-LibJS callers: URLPattern, HTML input pattern handling,
and the places in LibHTTP that only needed token validation.
Where a full regex engine was unnecessary, replace those call sites with
direct character checks. Also update focused LibURL, LibHTTP, and WPT
coverage for the migrated callers and corrected surrogate handling.
This allows us to disable test output, which performs expensive assert
tracking. This was making our imported tests run significantly slower
than tests run via `WPT.sh`.
Formatting the output ourselves also allows us to remove unnecessary
information from the test output.
This commit also rebaselines all existing imported WPT tests to follow
the new format.
