Technology sorting: Round-robin excludes same node key
Technology sorting: Round-robin excludes same node key

Don't "round-robin" between technologies on different nodes which have
an identical key. This is typically the case when an endpoint has gas
and electrical technologies.

This prevents technologies on the same node from being processed out of
the intended order (as defined by ConstraintOrder and TechnologyOrder).o

Closes #1606

quintel/etmoses,quintel/etmoses,quintel/etmoses,quintel/etmoses,quintel/etmoses