Fix anchoring [#3599]
Closes #3599 (closed). Partially reverts !1054 (merged) and introduces an alternative mechanism that allows DN->DN anchor signatures to be used to validate DN->BVN anchor signatures.
Changelog: fix
Closes #3599 (closed). Partially reverts !1054 (merged) and introduces an alternative mechanism that allows DN->DN anchor signatures to be used to validate DN->BVN anchor signatures.
Changelog: fix