Add memory backend

[prabirshrestha]

Any plans to add memory backend? I see it is mentioned in README.

Might be could reuse existing libraries such as https://lib.rs/crates/stretto or https://lib.rs/crates/moka?

[singulared]

Hi, thanks for your attention to this project!
Of course, we have plans to integrate the in-memory backend. It's one of our high-priority goals at this moment.

[AndreyErmilov]

Hi @prabirshrestha, we are about to release a new version of Hitbox based on Tower service infrastructure. So I would like to ask you, is it important for you to have in-memory backend in Actix-based version of Hitbox or is it not so important and you don't mind switching to Tower / Axum?

[prabirshrestha]

I'm looking it to use in Salvo and a worker so not sure how it would be related to actix or tower/Axum as I would expect the redis and memory backend to be agnostic of a web framework.