Investigate using upstream `url` parser

`adblock-rust`'s URL parsing is an in-tree fork of some files from the `rust-url` project.

According to https://github.com/brave/adblock-rust/commit/eed6eb001393475b9b491667b43cb268a8adae9b, it was done this way in order to slim down the full URL parser, likely for performance reasons. That being said, it's now a ~5 year old implementation that hasn't received any security updates or bugfixes.

If possible, I'd prefer to get this situation sorted out by using a well-audited upstream implementation, whether that is directly from `rust-url` or elsewhere.

Start by reviewing the in-tree URL parser fork and the referenced rust-url commit eed6eb001393475b9b491667b43cb268a8adae9b. Compare current parsing behavior and dependencies with rust-url or another audited upstream implementation, including the performance rationale. Done means the project has a justified upstream-parser direction that addresses maintenance and security concerns.

Written by the indexing model from the issue text.