Makes async traits in the SDK be Send

[grarco]

Describe your changes

Requires the Send bound on the async_traitss in the SDK. This allow the usage of the SDK in an environment which is both async and multithread (see https://rust-lang.github.io/async-book/07_workarounds/03_send_approximation.html).

Indicate on which release or other PRs this topic is based on

v0.22.0

Checklist before merging to draft

• I have added a changelog
• Git history is in acceptable state

[mariari]

Looks good, Thanks for the changelog.

[sug0]

I think this will be a problem for the namada interface; see rustwasm/wasm-bindgen#2833

and also https://github.com/anoma/namada-interface/blob/2ccc40b1a5092373a1223c55a74d3dcaa2258d6c/packages/shared/lib/src/rpc_client.rs#L16C3-L20

We can gate the ability to send futures across threads with something like:

#[cfg_attr(not(feature = "send-sdk-client"), async_trait(?Send))]
#[cfg_attr(feature = "send-sdk-client", async_trait)]
trait Client { ... }

[Fraccaman]

@sug0 yeah thats what we were also thinking! We asked @jurevans to test this branch, lets see how it goes

[jurevans]

Tested, and works well for me!