Fixes z-index bug in option grid
Fixes z-index bug in option grid

The collapsible form was covered by subsequent (invisible) option
cells and therefor the input elements in the form could not gain
focus. I incremented the z-index (and gave the form container a
relative position!) to fix this.

in-toto/layout-web-tool,in-toto/layout-web-tool,in-toto/layout-web-tool