Add a Collapse All / Expand all button to the company org chart

Add a button at the top of the org chart that allows the user to toggle between collapsing/expanding all the nodes by clicking on the button.

Default org chart state should be to be fully expanded.

Button text:

• If all nodes are expanded: Collapse all
• If any node is collapsed: Expand all

Reference: https://gitlab.slack.com/archives/C3MAZRM8W/p1568416800345400?thread_ts=1568366463.339100&cid=C3MAZRM8W