more resilient subsystems (#1908)

* backing: extract log target

* bitfield-signing: extract log target

* utils: fix a typo

* provisioner: extract log target

* candidate selection: remove unused error variant

* bitfield-distribution: change the return type of run

* pov-distribution: extract log target

* collator-protocol: simplify runtime request

* collation-generation: do not exit early on error

* collation-generation: do not exit on double init

* collator-protocol: do not exit on errors and rename LOG_TARGET

* collator-protocol: a workaround for ununused imports warning

* Update node/network/bitfield-distribution/src/lib.rs

* collation-generation: elevate warn! to error!

* collator-protocol: fix imports

* post merge fix

* fix compilation

polkadot/node/network/collator-protocol/src/lib.rs

@@ -43,7 +43,7 @@ use polkadot_node_subsystem_util::{
 mod collator_side;
 mod validator_side;
 
-const TARGET: &'static str = "colp";
+const LOG_TARGET: &'static str = "collator_protocol";
 const REQUEST_TIMEOUT: Duration = Duration::from_secs(1);
 
 #[derive(Debug, Error)]
@@ -140,7 +140,7 @@ where
 	Context: SubsystemContext<Message = CollatorProtocolMessage>,
 {
 	trace!(
-		target: TARGET,
+		target: LOG_TARGET,
 		"Reputation change of {:?} for peer {:?}", rep, peer,
 	);