Refactor: scheduler: add a parameter to pe__is_newer_op() indicating whether the two operations are on the same node by default

The on_node attribute was added to last_failure as of 1.1.13 (via
8b3ca1c) and the other entries as of 1.1.12 (via 0b07b5c).

In case that any of the lrm_rsc_op entries doesn't have on_node
attribute, we need to explicitly tell whether the two operations are on
the same node.