cmd/devp2p: update eth/snap protocol test suites for PoS (#28340)

Here we update the eth and snap protocol test suites with a new test chain,
created by the hivechain tool. The new test chain uses proof-of-stake. As such,
tests using PoW block propagation in the eth protocol are removed. The test suite
now connects to the node under test using the engine API in order to make it
accept transactions. 

The snap protocol test suite has been rewritten to output test descriptions and
log requests more verbosely.

---------

Co-authored-by: Felix Lange <fjl@twurst.com>

core/rawdb/chain_freezer.go

@@ -131,7 +131,7 @@ func (f *chainFreezer) freeze(db ethdb.KeyValueStore) {
 			continue
 
 		case *number < threshold:
-			log.Debug("Current full block not old enough", "number", *number, "hash", hash, "delay", threshold)
+			log.Debug("Current full block not old enough to freeze", "number", *number, "hash", hash, "delay", threshold)
 			backoff = true
 			continue
 

core/txpool/legacypool/legacypool.go

@@ -977,6 +977,7 @@ func (pool *LegacyPool) Add(txs []*types.Transaction, local, sync bool) []error
 		// in transactions before obtaining lock
 		if err := pool.validateTxBasics(tx, local); err != nil {
 			errs[i] = err
+			log.Trace("Discarding invalid transaction", "hash", tx.Hash(), "err", err)
 			invalidTxMeter.Mark(1)
 			continue
 		}