getbundleobsmarker: prevent crash from filtered content (issue4616) The discovery may discover common markers on non-served nodes. This lead to crash when building the obsmarker part.

test-wireproto: add some obsmarker discovery usage. The old code was never checking that the discovery were skipping common markers. This is now done.

test-wireprotocol: test with both bundle1 and bundle2 Bundle two is becoming the major way of exchanging things now. We duplicate the test and ensure the default version runs using bundle2.