Add WASI support for gloo-history.

[langyo]

I've been trying to use yew to render the page into the static HTML string on WASI. However, gloo-history cannot distinguish the browser WASM target (wasm32-unknown-unknown with wasm-bindgen) and WASI target (wasm32-wasi), and it would choose wrong functions for wasm32-*.

I have fixed it by using target_os, and it would fix the problem.

[ranile]

Can you make it use cfg(target_os = "wasi") instead of a feature

That should make the wasi feature unnecessary and handle the compilation accordingly. Other than that, it looks good.

It would be great if you could also update CI to run tests on WASI target (using wasmtime) though

[langyo]

Can you make it use cfg(target_os = "wasi") instead of a feature

That should make the wasi feature unnecessary and handle the compilation accordingly. Other than that, it looks good.

It would be great if you could also update CI to run tests on WASI target (using wasmtime) though

It's so new that when I looked through the documentation, it didn't even mention that the value of target_os can be wasi...

I tested it on the latest stable compiler and it works. I'll push the modified version later.

[ranile]

Thanks! Perhaps this is a good thing to update in the Rust documentation as well