Make BlockImport and Verifier async (#8472)

* Make grandpa work

* Introduce `SharedData`

* Add test and fix bugs

* Switch to `SharedData`

* Make grandpa tests working

* More Babe work

* Make it async

* Fix fix

* Use `async_trait` in sc-consensus-slots

This makes the code a little bit easier to read and also expresses that
there can always only be one call at a time to `on_slot`.

* Make grandpa tests compile

* More Babe tests work

* Fix network test

* Start fixing service test

* Finish service-test

* Fix sc-consensus-aura

* Fix fix fix

* More fixes

* Make everything compile *yeah*

* Fix build when we have Rust 1.51

* Update client/consensus/common/src/shared_data.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/common/src/shared_data.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/common/src/shared_data.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/common/src/shared_data.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/common/src/shared_data.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/babe/src/tests.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Update client/consensus/babe/src/tests.rs

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

* Fix warning

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

substrate/Cargo.lock

@@ -4171,6 +4171,7 @@ dependencies = [
  "frame-benchmarking",
  "frame-support",
  "frame-system",
+ "futures 0.3.13",
  "node-primitives",
  "node-runtime",
  "node-testing",
@@ -7106,6 +7107,7 @@ dependencies = [
 name = "sc-consensus"
 version = "0.9.0"
 dependencies = [
+ "parking_lot 0.11.1",
  "sc-client-api",
  "sp-blockchain",
  "sp-consensus",
@@ -7116,6 +7118,7 @@ dependencies = [
 name = "sc-consensus-aura"
 version = "0.9.0"
 dependencies = [
+ "async-trait",
  "derive_more",
  "futures 0.3.13",
  "futures-timer 3.0.2",
@@ -7157,6 +7160,7 @@ dependencies = [
 name = "sc-consensus-babe"
 version = "0.9.0"
 dependencies = [
+ "async-trait",
  "derive_more",
  "fork-tree",
  "futures 0.3.13",
@@ -7243,8 +7247,8 @@ version = "0.9.0"
 dependencies = [
  "fork-tree",
  "parity-scale-codec 2.0.1",
- "parking_lot 0.11.1",
  "sc-client-api",
+ "sc-consensus",
  "sp-blockchain",
  "sp-runtime",
 ]
@@ -7254,6 +7258,7 @@ name = "sc-consensus-manual-seal"
 version = "0.9.0"
 dependencies = [
  "assert_matches",
+ "async-trait",
  "derive_more",
  "futures 0.3.13",
  "jsonrpc-core",
@@ -7291,6 +7296,7 @@ dependencies = [
 name = "sc-consensus-pow"
 version = "0.9.0"
 dependencies = [
+ "async-trait",
  "derive_more",
  "futures 0.3.13",
  "futures-timer 3.0.2",
@@ -7442,6 +7448,7 @@ name = "sc-finality-grandpa"
 version = "0.9.0"
 dependencies = [
  "assert_matches",
+ "async-trait",
  "derive_more",
  "dyn-clone",
  "finality-grandpa",
@@ -7680,6 +7687,7 @@ name = "sc-network-test"
 version = "0.8.0"
 dependencies = [
  "async-std",
+ "async-trait",
  "futures 0.3.13",
  "futures-timer 3.0.2",
  "libp2p",
@@ -7860,6 +7868,7 @@ name = "sc-service"
 version = "0.9.0"
 dependencies = [
  "async-std",
+ "async-trait",
  "directories",
  "exit-future",
  "futures 0.1.31",
@@ -8665,6 +8674,7 @@ dependencies = [
 name = "sp-consensus"
 version = "0.9.0"
 dependencies = [
+ "async-trait",
  "futures 0.3.13",
  "futures-timer 3.0.2",
  "libp2p",
@@ -9488,6 +9498,7 @@ dependencies = [
 name = "substrate-test-client"
 version = "2.0.1"
 dependencies = [
+ "async-trait",
  "futures 0.1.31",
  "futures 0.3.13",
  "hash-db",
@@ -9519,6 +9530,7 @@ dependencies = [
  "frame-support",
  "frame-system",
  "frame-system-rpc-runtime-api",
+ "futures 0.3.13",
  "log",
  "memory-db",
  "pallet-babe",