Make candidate validation timeouts configurable (#4001)

* pvf: make execution timeout configurable

* guide: add timeouts to candidate validation params

* add timeouts to candidate validation messages

* fmt

* port backing to use the backing pvf timeout

* port approval-voting to use the execution timeout

* port dispute participation to use the correct timeout

* fmt

* address grumbles & test failure

polkadot/node/core/approval-voting/src/lib.rs

@@ -27,7 +27,7 @@ use polkadot_node_primitives::{
 	approval::{
 		BlockApprovalMeta, DelayTranche, IndirectAssignmentCert, IndirectSignedApprovalVote,
 	},
-	SignedDisputeStatement, ValidationResult,
+	SignedDisputeStatement, ValidationResult, APPROVAL_EXECUTION_TIMEOUT,
 };
 use polkadot_node_subsystem::{
 	errors::RecoveryError,
@@ -2235,6 +2235,7 @@ async fn launch_approval(
 					validation_code,
 					candidate.descriptor.clone(),
 					available_data.pov,
+					APPROVAL_EXECUTION_TIMEOUT,
 					val_tx,
 				)
 				.into(),