Switch to reqwest

[gferon]

Switch the concrete implementation of both the HTTP client to reqwest and reqwest-websocket which are powered behind the scenes by exactly the same libraries we are currently using (namely, hyper and tokio-tungstenite).

• Using a higher level builder-style API makes it easier to add support for new endpoints, and removes a lot of glue code we had to acquire over the year (the code looks now much closer to PushService.kt).
• reqwest::Client is now shared by both HTTP requests and the Websocket
• Remove one level of sink and stream in the websocket impl (since you don't have to forward messages to the concrete implementation)
• Introduce a no-op trait called SignalServiceResponse which is implemented for both reqwest::Response and WebSocketResponseMessage to let us share the HTTP status error handling (the one that handles mismatched sessions, etc.) - this is IMO a big improvement and will avoid any sort of drifting in the future

[direc85]

+573 −1,050

Everybody liked that

(Except Clippy. Clippy has no chill.)

I gave this a quick read and it really seems to simmer the code down nicely!

[gferon]

+573 −1,050

Everybody liked that

(Except Clippy. Clippy has no chill.)

I gave this a quick read and it really seems to simmer the code down nicely!

I have ruined my statistics a little bit by introducing a better abstraction for handling errors (which means we don't have duplicated logic in PushService and WebSocketService anymore 🎉) - however, I believe the tradeoff of a smaller statistical achievement for a higher quality library is worth it 🧌

I think this is ready for review, I will not touch this PR again before it becomes an insatiable monster. I still believe it is quite OK to test and will be running presage on top of it for the next few days (the only part that I'm worried about would be attachments, but this can easily be tested.)

[rubdos]

Haven't looked into detail too much yet, but this looks very good already. I suggest we also make a WF build with this and run it some days.

[rubdos]

Whisperfish tests: https://gitlab.com/whisperfish/whisperfish/-/merge_requests/639