Action buttons below request body table should only be shown when examples tab selected

[marshmn]

The action buttons below the request body table ('Fill Example', 'Clear', 'Try') only really make sense in context of the examples tab. If you have the schema tab open and you click the 'Clear' button for example, you don't see the effect of that until you switch back to the examples tab, which can be confusing.

It would be better if these buttons were only visible when the schema tab is selected.