Class ToolButtonDefault

Example with an icon classes:

   <gmf-tool-button slot="tool-button" iconClasses="fa fa-print" panelName="my-panel"></gmf-tool-button>

Example with a slot:

   <gmf-tool-button slot="tool-button" panelName="my-panel">
     <span>
       <i class="fa fa-mouse-pointer"></i>
     </span>
   </gmf-tool-button>