localrepo: Parse conflict information even without files
The output of git-merge-tree(1) contains conflict information. This is in the form of
<OID of toplevel tree>
<Conflicted file info>
<Informational messages>
But sometimes the conflicts arise from directory renames and as such
the Conflicted file info
section can be empty. Let's consider this
scenario and parse the output from git-merge-tree(1) without throwing an
error.
Part of #5098 (closed)
Edited by Karthik Nayak