Isolate URL object

[AntoinePrv]

• Hide CURL
• Refactor URLHandler as a URL class with strong invariant.
• Manage '%' encoding.
• Rewrite a number of function to make them independent of CURL /
• Add many tests
• Close Wrap curl functions in url files #2611

[AntoinePrv]

I'm merging for moving forward on other PR and fixing the CI, but feel free to add reviews, I will implement them in another PR.

[AntoinePrv]

@Hind-M @Klaim @JohanMabille Do you think it is a good idea to use fs::path as the path component of this URL?
I like the idea of being able to manipulate a path as a path and not a string, but this come with a number of issues on Windows...
If only we had a split Unixpath/WindowsPath/Path like in Python...

[Hind-M]

@Hind-M @Klaim @JohanMabille Do you think it is a good idea to use fs::path as the path component of this URL? I like the idea of being able to manipulate a path as a path and not a string, but this come with a number of issues on Windows... If only we had a split Unixpath/WindowsPath/Path like in Python...

Hmm I guess you won't know if you don't give it a try ^^

[Klaim]

Do you think it is a good idea to use fs::path as the path component of this URL?

While I agree it would be nice to have a path type for this, fs::path is designed specifically for filesystem paths and they are not working the same as url paths so I worry that there would be issues. Also internal storage of fs::path is implementation-dependent so thinknig about these like special string can lead to surprising behavior.
However, I wonder how hard would it be to make a very basic url path type just wrapping a std::string (assuming utf-8) ?

[JohanMabille]

@Hind-M @Klaim @JohanMabille Do you think it is a good idea to use fs::path as the path component of this URL? I like the idea of being able to manipulate a path as a path and not a string ...

I think this would be a wrong good idea ;) Especially when you have API like this one:

        /**
         * Append a sub path to the current path.
         *
         * Contrary to `std::filesystem::path::append`, this always append and never replace
         * the current path, even if @p subpath starts with a '/'.
         */
        auto append_path(std::string_view subpath) -> URL&;

If the path is stored (and returned) as a fs::path object, this would definitely create confusion. Also it is quite easy to build a fs::path from the path component of the URL when it is required / makes sense.

[JohanMabille]

Post merge review: LGTM , nothing to change so far.