GHSA-W74X-V6F9-J3XG fast-uri vulnerable to URI scheme spoofing via percent-encoded scheme decoding

Impact fast-uri percent-decodes the scheme component with the legacy global unescape before validating it, so an input whose decoded scheme is a valid but dangerous token is emitted as a live scheme. RFC 3986 section 3.1 does not allow percent-encoding in a scheme, so no RFC or WHATWG parser trea...