Merge #19252: test: wait for disconnect in disconnect_p2ps + bloomfilter test followups

9a40cfc558 [refactor] use waiting inside disconnect_p2ps (gzhao408)
aeb9fb414e [test] wait for disconnect_p2ps to be reflected in getpeerinfo (gzhao408)
e81942d2e1 [test] logging and style followups for bloomfilter tests (gzhao408)

Pull request description:

  Followup to #19083 which adds bloomfilter-related tests.

  1. Make test_node `disconnect_p2ps` wait until disconnection is complete to avoid race conditions (and not place the burden on tests) from MarcoFalke's [comment](https://github.com/bitcoin/bitcoin/pull/19083#discussion_r437383989). And clean up any redundant `wait_until`s in the functional tests.
  2. Clean up style + logging in p2p_filter.py and p2p_nobloomfilter_messages.py and jonatack's other [comments](https://github.com/bitcoin/bitcoin/pull/19083#pullrequestreview-428955784)

ACKs for top commit:
  jonatack:
    Code review ACK 9a40cfc from re-reviewing the diff and `git range-diff 5cafb46 8386ad5 9a40cfc`
  MarcoFalke:
    ACK 9a40cfc558 🐂

Tree-SHA512: 2e14b1c12fc08a355bd5ccad7a2a734a4ccda4bc7dc7bac171cb57359819fc1599d764290729af74832fac3e2be258c5d406c701e78ab6d7262835859b9a7d87

test/functional/test_framework/test_node.py

@@ -23,6 +23,7 @@ import sys
 
 from .authproxy import JSONRPCException
 from .descriptors import descsum_create
+from .messages import MY_SUBVERSION
 from .util import (
     MAX_NODES,
     append_config,
@@ -549,11 +550,16 @@ class TestNode():
         assert self.p2ps, self._node_msg("No p2p connection")
         return self.p2ps[0]
 
+    def num_connected_mininodes(self):
+        """Return number of test framework p2p connections to the node."""
+        return len([peer for peer in self.getpeerinfo() if peer['subver'] == MY_SUBVERSION])
+
     def disconnect_p2ps(self):
         """Close all p2p connections to the node."""
         for p in self.p2ps:
             p.peer_disconnect()
         del self.p2ps[:]
+        wait_until(lambda: self.num_connected_mininodes() == 0)
 
 
 class TestNodeCLIAttr: