Make subxt-core ready for publishing (#1508)

* Move Extrinsic decoding things to subxt_core and various tidy-ups

* A couple more fixes and fmt

* first pass moving tx logic to subxt_core

* cargo fmt

* fix wasm example

* clippy

* more clippy

* WIP Adding examples and such

* Move storage functionality more fully to subxt_core and nice examples for storage and txs

* Add example for events

* consistify how addresses/payloads are exposed in subxt-core and add runtime API fns

* Add runtime API core example

* fmt

* remove scale-info patch

* Add a little to the top level docs

* swap args around

* clippy

* cargo fmt and fix wasm-example

* doc fixes

* no-std-ise new subxt-core additions

* alloc, not core

* more no-std fixes

* A couple more fixes

* Add back extrinsic decode test

subxt/src/backend/unstable/mod.rs

@@ -416,7 +416,10 @@ impl<T: Config + Send + Sync + 'static> Backend<T> for UnstableBackend<T> {
                     RuntimeEvent::Valid(ev) => ev,
                 };
 
-                let runtime_version = RuntimeVersion::new(runtime_details.spec.spec_version, runtime_details.spec.transaction_version);
+                let runtime_version = RuntimeVersion {
+                    spec_version: runtime_details.spec.spec_version,
+                    transaction_version: runtime_details.spec.transaction_version
+                };
                 std::future::ready(Some(Ok(runtime_version)))
             });