Add instrumentation, with performance profiling capability (#4132)

* Implement instrumentation for performance profiling

* Add profiling to runtime functions declared in `decl_module` inc.
`on_initialize` and `on_finalize`

* Remove changes

* add docs, tidy up

* fix versions

* fix copyright date

* switch to hashmap and instant

* update example

* update example

* implement receiver for logger and make default

* fix comment

* use `if_std!` macro

* remove whitespace

* fix whitespace

* fix nits

substrate/client/service/src/config.rs

@@ -98,6 +98,10 @@ pub struct Configuration<C, G, E = NoExtension> {
 	///
 	/// Should only be set when `node` is running development mode.
 	pub dev_key_seed: Option<String>,
+	/// Tracing targets
+	pub tracing_targets: Option<String>,
+	/// Tracing receiver
+	pub tracing_receiver: substrate_tracing::TracingReceiver,
 }
 
 /// Configuration of the database of the client.
@@ -156,6 +160,8 @@ impl<C, G, E> Configuration<C, G, E> where
 			disable_grandpa: false,
 			keystore_password: None,
 			dev_key_seed: None,
+			tracing_targets: Default::default(),
+			tracing_receiver: Default::default(),
 		};
 		configuration.network.boot_nodes = configuration.chain_spec.boot_nodes().to_vec();