title: insert space between cells in list view javaFX
body: <p>I want to create gap between listview cells but i didn't find any suitable method to do this task.
  Is there any method in css or java code to create gap between them?</p>
  
  <p>Here is what I am looking for:</p>
  
  <p><img src="https://i.stack.imgur.com/TzSBZ.png" alt="enter image description here">
  Thanks in advances,</p>