evolvestate: store info about relocation while resolving content-divergence
While resolving content-divergence when they are on different parents, we
relocate one of the node to parent of another one and this can lead to conflicts
sometimes. So we need to store information about that state in evolvestate so
that we can use that when user does `hg evolve --continue` or `--stop` or
`--abort`.
Now that we make sure, we store the new other node in evolvestate, we fix the
behavior of handling the relocated commit and merge the right changesets.