Slider View: Create Slider App wizard config sections should have triangles

In the create slider app wizard's Configuration page, we show configuration sections without any triangles indicating that they can be expanded and collapsed.

Contrast that with Ambari config sections which have triangle indicating collapsed/expanded (image attached).

Also, the entire config bar should be clickable, not just the text link. It is hard to click only on the text. Ambari configs allow clicking on the entire section bar.