Finish migration to v2 primitives (#5037)

* remove v0 primitives from polkadot-primitives

* first pass: remove v0

* fix fallout in erasure-coding

* remove v1 primitives, consolidate to v2

* the great import update

* update runtime_api_impl_v1 to v2 as well

* guide: add `Version` request for runtime API

* add version query to runtime API

* reintroduce OldV1SessionInfo in a limited way

polkadot/node/network/approval-distribution/src/lib.rs

@@ -40,7 +40,7 @@ use polkadot_node_subsystem_util::{
 	metrics::{self, prometheus},
 	MIN_GOSSIP_PEERS,
 };
-use polkadot_primitives::v1::{
+use polkadot_primitives::v2::{
 	BlockNumber, CandidateIndex, Hash, ValidatorIndex, ValidatorSignature,
 };
 use std::collections::{hash_map, BTreeMap, HashMap, HashSet};

polkadot/node/network/approval-distribution/src/tests.rs

@@ -28,7 +28,7 @@ use std::time::Duration;
 
 type VirtualOverseer = test_helpers::TestSubsystemContextHandle<ApprovalDistributionMessage>;
 
-fn dummy_signature() -> polkadot_primitives::v1::ValidatorSignature {
+fn dummy_signature() -> polkadot_primitives::v2::ValidatorSignature {
 	sp_core::crypto::UncheckedFrom::unchecked_from([1u8; 64])
 }