fatxpool: check old/new pool network interactions

[michalkucharczyk]

We need to check what would be behavior of the network where there are nodes with both old and new pool is enabled.
In essence it should be cross-checked that reputation of the nodes is not decreased bc of different view on the ready set.

[Polkadot-Forum]

This issue has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/the-fork-aware-transaction-pool/10468/6

[wilwade]

We have been running various combinations of old and new tx pools on the Frequency Testnet for ~24 hours now. All appears to be fine even under the load of the testnet e2e tests we run (all in parallel).