qa: test cached failure for compact block

Submit the block with an invalid transaction Script again, leading to
CACHED_INVALID being returned by AcceptBlockHeader(). Ensure that also this
code path does not lead to a disconnection.

This was previously untested, as can be checked with the following diff:
```diff
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 0c4a89c44cb..e8e0c805367 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1814,10 +1814,10 @@ void PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
         {
             // Discourage outbound (but not inbound) peers if on an invalid chain.
             // Exempt HB compact block peers. Manual connections are always protected from discouragement.
-            if (peer && !via_compact_block && !peer->m_is_inbound) {
+            //if (peer && !via_compact_block && !peer->m_is_inbound) {
                 if (peer) Misbehaving(*peer, message);
                 return;
-            }
+            //}
             break;
         }
     case BlockValidationResult::BLOCK_INVALID_HEADER:
```

test/functional/p2p_compactblocks.py

@@ -744,6 +744,13 @@ class CompactBlocksTest(BitcoinTestFramework):
         assert_not_equal(node.getbestblockhash(), block.hash_hex)
         test_node.sync_with_ping()
 
+        # The failure above was cached. Submitting the compact block again will returned a cached
+        # consensus error (the code path is different) and still not get us disconnected (nor
+        # advance the tip).
+        test_node.send_and_ping(msg)
+        assert_not_equal(node.getbestblockhash(), block.hash_hex)
+        test_node.sync_with_ping()
+
     # Helper for enabling cb announcements
     # Send the sendcmpct request and sync headers
     def request_cb_announcements(self, peer):