Cover the remaining bmp-tcp-in metrics with at least some tests.
The biggest changes are actually not the tests themselves but the preparation for them, including:
Factor similar testable TCP traits out of bgp-tcp-in and bmp-tcp-in into new modules common::net and tests::util::net.
Tweaks to the test metric capture and asserting for testing the BMP received message count by message type metric, as that has multiple labels per metric (router id and msg type) and until now only one label per metric was tested.
Cover the remaining
bmp-tcp-inmetrics with at least some tests.The biggest changes are actually not the tests themselves but the preparation for them, including: