Switch GrandPa to std futures (replaces #3909) (#4612)

* Switch GrandPa to new futures

* Work on making tests work

* until_imported tests working again

* Work on switching tests to stable futures

* Modifications

* Re-add test as #[ignore]

* Don't ignore

* Add manual unpins

* Remove Header import

* Return concrete Sink type

* Switch to crates.io finality-grandpa version

* Remove use statement that slipped in

* Fix some nitpicks

* Remove unpin from i

* Fixed typo

* Move futures01 to dev-deps

* Fix nitpicks

* Update client/finality-grandpa/src/communication/mod.rs

Co-Authored-By: André Silva <andre.beat@gmail.com>

* nitpicking

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>
Co-authored-by: André Silva <andre.beat@gmail.com>

substrate/bin/node/cli/src/service.rs

@@ -110,10 +110,7 @@ macro_rules! new_full_start {
 /// concrete types instead.
 macro_rules! new_full {
 	($config:expr, $with_startup_data: expr) => {{
-		use futures::{
-			prelude::*,
-			compat::Future01CompatExt
-		};
+		use futures::prelude::*;
 		use sc_network::Event;
 
 		let (
@@ -220,7 +217,7 @@ macro_rules! new_full {
 					service.network(),
 					service.on_exit(),
 					service.spawn_task_handle(),
-				)?.compat().map(drop));
+				)?);
 			},
 			(true, false) => {
 				// start the full GRANDPA voter
@@ -237,7 +234,7 @@ macro_rules! new_full {
 				// the GRANDPA voter task is considered infallible, i.e.
 				// if it fails we take down the service with it.
 				service.spawn_essential_task(
-					grandpa::run_grandpa_voter(grandpa_config)?.compat().map(drop)
+					grandpa::run_grandpa_voter(grandpa_config)?
 				);
 			},
 			(_, true) => {