fix: Complete snowbridge pezpallet rebrand and critical bug fixes

- snowbridge-pezpallet-* → pezsnowbridge-pezpallet-* (201 refs)
- pallet/ directories → pezpallet/ (4 locations)
- Fixed pezpallet.rs self-include recursion bug
- Fixed sc-chain-spec hardcoded crate name in derive macro
- Reverted .pezpallet_by_name() to .pallet_by_name() (subxt API)
- Added BizinikiwiConfig type alias for zombienet tests
- Deleted obsolete session state files

Verified: pezsnowbridge-pezpallet-*, pezpallet-staking,
pezpallet-staking-async, pezframe-benchmarking-cli all pass cargo check

pezbridges/relays/finality/src/lib.rs

@@ -0,0 +1,93 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! This crate has single entrypoint to run synchronization loop that is built around finality
+//! proofs, as opposed to headers synchronization loop, which is built around headers. The headers
+//! are still submitted to the target node, but are treated as auxiliary data as we are not trying
+//! to submit all source headers to the target node.
+
+pub use crate::{
+	base::{FinalityPipeline, SourceClientBase},
+	finality_loop::{
+		metrics_prefix, run, FinalitySyncParams, HeadersToRelay, SourceClient, TargetClient,
+	},
+	finality_proofs::{FinalityProofsBuf, FinalityProofsStream},
+	sync_loop_metrics::SyncLoopMetrics,
+};
+
+use bp_header_pez_chain::ConsensusLogReader;
+use relay_utils::{FailedClient, MaybeConnectionError};
+use std::fmt::Debug;
+
+mod base;
+mod finality_loop;
+mod finality_proofs;
+mod headers;
+mod mock;
+mod sync_loop_metrics;
+
+/// Finality proofs synchronization pipeline.
+pub trait FinalitySyncPipeline: FinalityPipeline {
+	/// A reader that can extract the consensus log from the header digest and interpret it.
+	type ConsensusLogReader: ConsensusLogReader;
+	/// Type of header that we're syncing.
+	type Header: SourceHeader<Self::Hash, Self::Number, Self::ConsensusLogReader>;
+}
+
+/// Header that we're receiving from source node.
+pub trait SourceHeader<Hash, Number, Reader>: Clone + Debug + PartialEq + Send + Sync {
+	/// Returns hash of header.
+	fn hash(&self) -> Hash;
+	/// Returns number of header.
+	fn number(&self) -> Number;
+	/// Returns true if this header needs to be submitted to target node.
+	fn is_mandatory(&self) -> bool;
+}
+
+/// Error that may happen inside finality synchronization loop.
+#[derive(Debug)]
+enum Error<P: FinalitySyncPipeline, SourceError, TargetError> {
+	/// Source client request has failed with given error.
+	Source(SourceError),
+	/// Target client request has failed with given error.
+	Target(TargetError),
+	/// Finality proof for mandatory header is missing from the source node.
+	MissingMandatoryFinalityProof(P::Number),
+	/// `submit_finality_proof` transaction failed
+	ProofSubmissionTxFailed {
+		#[allow(dead_code)]
+		submitted_number: P::Number,
+		#[allow(dead_code)]
+		best_number_at_target: P::Number,
+	},
+	/// `submit_finality_proof` transaction lost
+	ProofSubmissionTxLost,
+}
+
+impl<P, SourceError, TargetError> Error<P, SourceError, TargetError>
+where
+	P: FinalitySyncPipeline,
+	SourceError: MaybeConnectionError,
+	TargetError: MaybeConnectionError,
+{
+	fn fail_if_connection_error(&self) -> Result<(), FailedClient> {
+		match *self {
+			Error::Source(ref error) if error.is_connection_error() => Err(FailedClient::Source),
+			Error::Target(ref error) if error.is_connection_error() => Err(FailedClient::Target),
+			_ => Ok(()),
+		}
+	}
+}