Stack convergence detailed path

[vietj]

when a convergence fails we need to have the full path of dependencies instead of just the path leaves to help fixing the convergence issue.

i.e if A -> B -> C(v1) and D -> E -> C(v2)

now we know that A and D are in conflict on C, we should know the transitive path (at least one, there can be several) that leads to the conflict to ease its resolution