fix(engine/parallelGtw): end when no outgoing transitions

This commit adds a fix to the take all behavior of executions.
If no outgoing edges exist, the execution is ended. As a result, the
process does not get stuck any more.

Add a failing test case for the same problem inside sub processes.

Related to CAM-1684
Merge branch 'master' of github.com:camunda/camunda-bpm-platform