Silence known deprecation warnings (#2651)

* Silence known deprecation warnings

1. Prefixes known instances of usages of client.backend and client.import_lock with `#[allow(deprecated)]` to silence the warnings. 2. Remove file-global `#![allow(deprecated)]` used in these cases. Both to prevent us overlooking externally caused deprecation messages.

* fixing missing ;

* fix missing test cases

* move deprecated markers to make CI happy

* move deprecated markers to make CI happy

* attempt to fix the test

* bumping impl_version of node runtime

* Minor cleanup

substrate/core/consensus/babe/src/lib.rs

@@ -1079,11 +1079,15 @@ mod tests {
 				&inherent_data_providers, config.get()
 			).expect("Registers babe inherent data provider");
 
+
+			#[allow(deprecated)]
+			let select_chain = LongestChain::new(client.backend().clone(), client.import_lock().clone());
+
 			let babe = start_babe(BabeParams {
 				config,
 				local_key: Arc::new(key.clone().into()),
 				block_import: client.clone(),
-				select_chain: LongestChain::new(client.backend().clone(), client.import_lock().clone()),
+				select_chain,
 				client,
 				env: environ.clone(),
 				sync_oracle: DummyOracle,