Hide Tauri integration behind feature flag

[binarybaron]

We can hide the Tauri integration behind an optional tauri-integration feature flag. This would allow the swap (cli and asb) crate to be compiled without having to compile the tauri crate (meaning the library).

If our long term goal is for this fork to replace upstream, it might be beneficial.

This would fix the currently failing CI build action: https://github.com/UnstoppableSwap/xmr-btc-swap/actions/runs/10563121578/job/29262633363

[binarybaron]

@Einliterflasche What do you think?

[Einliterflasche]

Long term goal should probably be that tauri compilation works... But yeah, we could do that

[binarybaron]

Regardless of the CI it does make sense to me to still be able to compile the project entirely without Tauri

[Einliterflasche]

While that would be nice it would also require us to mark every bit of code that uses tauri functions with #[cfg(feat = tauri)]`, including imports... I mean, we could do that if we manage to keep the tauri code concentrated into a few areas

[binarybaron]

We could also delegate the calling of the emit function on the tauri handle (implementation of TauriEmitter) to the src-tauri crate. That way 'swap' will only include the trait definition and will not depend on the 'tauri' crate.

[Einliterflasche]

working on it in #37