deps: use polkadot-sdk umbrella crate (#1786)

* deps: unify usage of polkadot-sdk crates

* cargo fmt

* fix macro crate

* make tests compile

* fix more nits

* fix doc tests

* fix more nits

* more nits

* core: remove polkadot-sdk/std

* cargo fmt

* remove polkadot-sdk/std by default

* Update metadata/Cargo.toml

* remove more std

* Update Cargo.toml

subxt/src/events/events_client.rs

@@ -5,6 +5,7 @@
 use crate::backend::{Backend, BackendExt, BlockRef};
 use crate::{client::OnlineClientT, error::Error, events::Events, Config};
 use derive_where::derive_where;
+use polkadot_sdk::sp_crypto_hashing;
 use std::future::Future;
 
 /// A client for working with events.