Use cached session index to obtain executor params (#1190)

* Import changes from archieved repo

* Revert erroneous changes

* Fix more tests

* Resolve discussions

* Fix MORE tests

* approval-voting: launch_approval better interface (#1355)

---------

Co-authored-by: Javier Viola <javier@parity.io>
Co-authored-by: ordian <noreply@reusable.software>
Co-authored-by: ordian <write@reusable.software>

polkadot/node/overseer/examples/minimal-example.rs

@@ -76,6 +76,7 @@ impl Subsystem1 {
 			let msg = CandidateValidationMessage::ValidateFromChainState(
 				candidate_receipt,
 				PoV { block_data: BlockData(Vec::new()) }.into(),
+				Default::default(),
 				PvfExecTimeoutKind::Backing,
 				tx,
 			);