Add some instrumentation for new workflow engine service.
Add some instrumentation for new workflow engine service.

This means we now also track counts + timers for orquesta workflow and
action executions.

StackStorm/st2,StackStorm/st2,nzlosh/st2,StackStorm/st2,Plexxi/st2,Plexxi/st2,nzlosh/st2,Plexxi/st2,nzlosh/st2,StackStorm/st2,Plexxi/st2,nzlosh/st2