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/finality-grandpa/src/tests.rs

@@ -119,6 +119,7 @@ impl TestNetFactory for GrandpaTestNet {
 	{
 		match client {
 			PeersClient::Full(ref client) => {
+				#[allow(deprecated)]
 				let select_chain = LongestChain::new(
 					client.backend().clone(),
 					client.import_lock().clone()
@@ -676,6 +677,7 @@ fn transition_3_voters_twice_1_full_observer() {
 					"Peer #{} failed to sync", i);
 
 		let set: AuthoritySet<Hash, BlockNumber> = crate::aux_schema::load_authorities(
+			#[allow(deprecated)]
 			&**full_client.backend()
 		).unwrap();
 
@@ -765,6 +767,7 @@ fn transition_3_voters_twice_1_full_observer() {
 				.map(move |()| {
 					let full_client = client.as_full().expect("only full clients are used in test");
 					let set: AuthoritySet<Hash, BlockNumber> = crate::aux_schema::load_authorities(
+						#[allow(deprecated)]
 						&**full_client.backend()
 					).unwrap();
 
@@ -1035,6 +1038,7 @@ fn force_change_to_new_set() {
 
 			let full_client = peer.client().as_full().expect("only full clients are used in test");
 			let set: AuthoritySet<Hash, BlockNumber> = crate::aux_schema::load_authorities(
+				#[allow(deprecated)]
 				&**full_client.backend()
 			).unwrap();
 
@@ -1288,6 +1292,7 @@ fn voter_persists_its_votes() {
 				assert_eq!(net.lock().peer(0).client().info().unwrap().chain.best_number, 40,
 						   "Peer #{} failed to sync", 0);
 
+				#[allow(deprecated)]
 				let block_30_hash =
 					net.lock().peer(0).client().as_full().unwrap().backend().blockchain().hash(30).unwrap().unwrap();