See the new extensive doxygen in `url.hh`.
This fixes fetching gitlab: flakes.
Paths are now stored as a std::vector of individual path
segments, which can themselves contain path separators '/' (%2F).
This is necessary to make the Gitlab's /projects/ API work.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
This systematizes the way our s3:// URLs are parsed in filetransfer.cc.
Yoinked out and refactored out of [1].
[1]: https://github.com/NixOS/nix/pull/13752
Co-authored-by: Bernardo Meurer Costa <beme@anthropic.com>
