Form builder toolbox placement for better UX

[critzo]

Currently the form builder Toolbox is anchored to the top of the right column. As a survey is drafted, this means scrolling up and down constantly to add new elements. It would be great if the Toolbox could stay aligned with the end of the survey or closer to where the user is editing.

[jheretic]

Not sure how possible this is with the form builder widget we're using, but we can look into it!