add wasm support (#700)

* get started

* make it work again

* make it compile again

* Use async-wasm-feature of jsonrpsee from the master branch

* Ensure we enable JS feature of getrandom for the wasm target

* Update subxt/src/lib.rs

* update jsonrpsee

* fix CI

* cargo fmt

* fix wasm test

* fix grumbles

* exclude wasm-tests from workspace

To avoid leaking `jsonrpsee-web` feature into the workspace

Co-authored-by: Igor Matuszewski <xanewok@gmail.com>

subxt/src/lib.rs

@@ -140,6 +140,13 @@ use tokio as _;
 
 pub use subxt_macro::subxt;
 
+// Used to enable the js feature for wasm.
+#[cfg(target_arch = "wasm32")]
+pub use getrandom as _;
+
+#[cfg(all(feature = "jsonrpsee-ws", feature = "jsonrpsee-web"))]
+std::compile_error!("Both the features `jsonrpsee-ws` and `jsonrpsee-web` are enabled which are mutually exclusive");
+
 pub mod blocks;
 pub mod client;
 pub mod config;