Remove tokio dependencies (#2935)

* Remove dependencies on tokio

* Make service not depend on tokio

* Fix service tests

* Manually poll the import queue if failed to start

* Spawn all tasks at the end

* Remove executor from TelemetryOnConnect

* Remove TaskExecutor from offchain workers

* Remove TaskExecutor from AuthoritySetup

* Remove TaskExecutor from service

* Remove tokio dependency from RPC

* Remove finality-grandpa from WASM checks

* Fix offchain tests

* Line widths

* Fix RPC tests

* Fix service tests

* Fix bad futures polling

* Address some concerns

* Better error handling

* Is it the connectivity test that's not passing? I don't know, let's try

* Revert "Is it the connectivity test that's not passing? I don't know, let's try"

This reverts commit 28bbe51f0e2e4885fe1f901e11078604604cb212.

* Fix test

substrate/core/cli/src/lib.rs

@@ -645,7 +645,9 @@ where
 		None => Box::new(stdin()),
 	};
 
-	service::chain_ops::import_blocks::<F, _, _>(config, exit.into_exit(), file).map_err(Into::into)
+	let fut = service::chain_ops::import_blocks::<F, _, _>(config, exit.into_exit(), file)?;
+	tokio::run(fut);
+	Ok(())
 }
 
 fn revert_chain<F, S>(