txpool: don't maintain the pool during major sync (paritytech#13004)

* txpool: don't maintain the pool during major sync

Fix shall prevent from wasting the CPU during the major sync. No actions
are actually required in transaction pool during the major sync.

Fixes: paritytech#12903

* passing sync_oracle to maintain method

* fixed: builder, txpool tests

* do not maintain tx-pool if node gone out of sync

* EnactmentAction: all logic moved to EnactmentState

Tests to be done.

* maintain guard logic moved directly to MaintainedTransactionPool

* minor fixes

* EnactmentAction: all logic moved to EnactmentState (again)

* SyncOracle fixes here and there

* Update client/transaction-pool/src/enactment_state.rs

Co-authored-by: Bastian Köcher <git@kchr.de>

* Update client/transaction-pool/src/enactment_state.rs

Co-authored-by: Bastian Köcher <git@kchr.de>

* sync_oracle removed

* spelling + fmt + doc

* Review suggestions applied

* log::info -> debug

* Update client/transaction-pool/src/enactment_state.rs

Co-authored-by: Bastian Köcher <git@kchr.de>

* ".git/.scripts/commands/fmt/fmt.sh"

Co-authored-by: parity-processbot <>
Co-authored-by: Bastian Köcher <git@kchr.de>

client/transaction-pool/Cargo.toml

@@ -19,6 +19,7 @@ futures = "0.3.21"
 futures-timer = "3.0.2"
 linked-hash-map = "0.5.4"
 log = "0.4.17"
+num-traits = "0.2.8"
 parking_lot = "0.12.1"
 serde = { version = "1.0.136", features = ["derive"] }
 thiserror = "1.0.30"