the current save/apply buttons (basically the `bottomButtonBar` from the `form` taglig) floats the buttons over the form config when the form can not be fully displayed.

however this causes some issues (at least in automated testing), as these buttons often obscure the element we are trying to click on (even if just for a short while after the scroller has moved the page, and the elements reprositioned)

It would be nice if we could indicate that the page has more elements without obsucring them somehow.

https://github.com/jenkinsci/acceptance-test-harness/pull/619/files#diff-924ccb08900e51e37d8f6768a863e87795544b16c56986caa3047a709fb7d0c5R108