Improve debug log fields when executing requests

[orf]

First: this is a fantastic library, thank you! <3

One issue we've run into is that the logs are quite verbose. This MR makes the (very useful) sending/receiving debug! calls add fields with the method, status, uri, status and content length.

This enables one to set a logging directive like rustify::client[{success=false}]=debug to log all unsuccessful requests to the console, whilst skipping successful ones.

I also moved some verbose executing endpoint debug! calls to be trace! instead.

[stormshield-gt]

You can rebase on master, #24 should have fix the CI

[orf]

Done!

[stormshield-gt]

Thanks for your contribution!

[orf]

No, thank you for accepting it and your work on this library! ❤️