988024fe37 test: add check_node_connections in util (brunoerg)
Pull request description:
This function (`check_node_connections`) exists in `feature_anchors.py` and `p2p_add_connections.py` and does the same thing in both, this PR moves this function to util to avoid repetition and facilitate maintenance.
ACKs for top commit:
laanwj:
Code review ACK 988024fe37
Tree-SHA512: bf86c5659933539c72cb91ad587552b45c918be74d36fb429e78f3b954f01ed0855a85dd49aea35b432fbd18227c05eb3fec8b99c139c3509c39b19bccf6b7fd