Consolidate frame benchmarking into a frame crate (#4977)

This prs cleans up some of the frame benchmarking stuff:
- Move CLI into `frame-benchmarking-cli`. No frame related CLI should
exists in the default Substrate CLI.
- Move all traits and types related to frame benchmarking into the
`frame-benchmarking` trait. Frame types should be isolated in Frame.

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

@@ -53,6 +53,13 @@ pub enum Subcommand {
 		about = "Decode given block or extrinsic using current native runtime."
 	)]
 	Inspect(node_inspect::cli::InspectCmd),
+
+	/// The custom benchmark subcommmand benchmarking runtime pallets.
+	#[structopt(
+		name = "benchmark",
+		about = "Benchmark runtime pallets."
+	)]
+	Benchmark(frame_benchmarking_cli::BenchmarkCmd),
 }
 
 /// The `factory` command used to generate transactions.

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

@@ -43,12 +43,17 @@ where
 			cmd.init(&mut config, load_spec, &version)?;
 
 			let client = sc_service::new_full_client::<
-				node_runtime::Block,node_runtime::RuntimeApi, node_executor::Executor, _, _,
+				node_runtime::Block, node_runtime::RuntimeApi, node_executor::Executor, _, _,
 			>(&config)?;
 			let inspect = node_inspect::Inspector::<node_runtime::Block>::new(client);
 
 			cmd.run(inspect)
 		},
+		Some(Subcommand::Benchmark(cmd)) => {
+			cmd.init(&mut config, load_spec, &version)?;
+
+			cmd.run::<_, _, node_runtime::Block, node_executor::Executor>(config)
+		},
 		Some(Subcommand::Factory(cli_args)) => {
 			sc_cli::init(&cli_args.shared_params, &version)?;
 			sc_cli::init_config(&mut config, &cli_args.shared_params, &version, load_spec)?;