WASM cookies

[c-git]

I got cookies working for WASM to the best of my knowledge. I tested it in my use case and it works. I'm not sure how to add tests for the cookie functionality I added for WASM.

I also have one part of the code that I'm unsure of because I didn't see a clear translation between the native version and the WASM version.

Please let me know what you need me to do or change anything (including if the code I mentioned that I was unsure of is ok).

Edit:

If you need this functionality before the PR lands you can add the following to the bottom of your Cargo.toml. If you need me to rebase to keep up with changes to reqwest let me know (replying here would work as well) as I may not update unless a reason comes up such as I'm doing an updates on my dependencies or a security fixed comes out.

# https://doc.rust-lang.org/cargo/reference/overriding-dependencies.html#testing-a-bugfix
[patch.crates-io]
reqwest = { git = "https://github.com/c-git/reqwest.git", branch = "wasm-cookies" }

[c-git]

I rebased the PR and made a few lint related commits. I reviewed the code again in light of #1449 and they are very similar. I put a lot more of the code in wasm/client.rs but for the most part they seem to have a lot of the same things. Before this PR lands I would appreciate some feedback on:

• If there is a way I should add tests for this
• If the fact that we do not capture cookies during redirect loops is a problem. This is the native code that does not have a WASM counterpart. TODO for follow up on this.
• There is a clone of url that isn't needed but I left it to keep the API as similar as possible between WASM and Native. But the function is private so it's likely not a problem to make the change. I did a sample of the version without the clone here here.
• There is a clone that I did here to get around a lifetime restriction that I couldn't find a way to remove without making the code less easy to read.

[c-git]

PS. Maybe somewhere we should add a warning that WASM cookies won't work for WebSockets because according to

https://devcenter.heroku.com/articles/websocket-security#authentication-authorization

Since you cannot customize WebSocket headers from JavaScript, you’re limited to the “implicit” auth (i.e. Basic or cookies) that’s sent from the browser. Further, it’s common to have the server that handles WebSockets be completely separate from the one handling “normal” HTTP requests. This can make shared authorization headers difficult or impossible.

The emphasis above is mine. The way cookies are implemented right now for WASM is very similar to how it is done for native which means in the browser it has to use JavaScript to set the cookies in the header which is not allowed for WebSocket requests.