Propose an async client

[jmaupetit]

Is your feature request related to a problem? Please describe.

Thank you for this amazing project! 😍

While using this library in an asynchronous context (let's say in an asynchronous API), it would strongly improve performances if you also provide a deezer.AsyncClient. WDYT?

Describe alternatives you've considered

None for now.

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

Are you willing to resolve this issue by submitting a Pull Request?

• Yes, I have the time, and I know how to start.
• Yes, I have the time, but I don't know how to start. I would need guidance.
• No, I don't have the time, although I believe I could do it if I had the time...
• No, I don't have the time and I wouldn't even know how to start.

[browniebroke]

Yes, definitely open to add this. It was discussed in #804 and that was one of the drivers for moving from requests to httpx. Ideally I wanted to have an async client alongside the sync one, but that might end up causing a lot of code duplication...

Open to suggestion on how to best approach that.

[jmaupetit]

I didn't noticed this issue. I would definitely vote for an async client by default! IMO it's the best compromise as it's not limiting its sync usage.

Do you plan working on this? I can help 😉

[OkoyaUsman]

I needed this for a project and decided to implement it, can you review? thank you
cc: @browniebroke