Motivation

Currently, we don't have a registry of transaction requests made to other peers using the GetPooledTransactions message. As a result, we don't have a way to validate the peers' responses. We may also be requesting the same transaction from multiple peers, consuming more bandwidth.

Description

• Creates a PendingRequests structure to keep track of requests made.
• On a NewPooledTransactionHashes message, checks if the transactions have not been requested yet.
• On a PooledTransactions response, validates the response against the stored request.
• If the response is valid, removes the request from PendingRequests.
• Every 5 secs, removes the stale requests from the registry.
• On a peer_conn_failed event, removes the pending requests of the remote_node from the registry.
• Fixes eth/BlobViolations Hive test: This test sends a PooledTransactions message with invalid types and sizes. The test was previously passing because the transactions used in the test were also dummy.

Additionally, this PR changes how we handle errors when validating the transactions against our mempool before adding them:

• Stops disconnecting from peers on validation errors, as we may be one block behind the current head and invalidating transactions for insufficient balance. L1 P2P: penalize peers on invalid transactions #1806 was created.
• On receiving a Transactions message, filters and propagates only the valid transactions. This change brakes the Hive test eth/InvalidTxs since we are incorrectly considering valid two transactions in the test. InvalidTxs #1139 was created to fix this.

Closes #1415
Closes #1781
Closes #1416