title: How to prevent concurrent execution of jobs on the same node, but allow a few parallel steps execution
body: <p>I have multibranch job, whole pipeline runs on certain node. Currently I have a slaves with single executor, so multiple jobs cannot run on the same node. 
    I'd like to use parallel steps inside my pipeline, so I need to increase number of executors. What is the best way to prevent concurrent job execution?
    Such configuration was trivial with Jenkins freestyle job and Throttling plugin  - I simple used "Maximum Concurrent Builds Per Node".
    But in pipeline it seems that I cannot use "throttle" for whole pipeline, I need to use it for each step.
    Is there more elegant solution?</p>
  
  <p>TIA,
  Vitaly</p>