Editing a Data source URL: Fields should appear below collapsable component

[sachajudd]

After some discussion with @clarkepaul we've decided that it might make more sense when editing a data source URL that the fields appear below the Data source title rather than above.

Quick mock up of what this might look like:

To do: Currently still deciding if it would need a background colour.

[robbieaverill]

This could actually be a little tricky to achieve, because the field is a FormField and the title is a GridFieldComponent (part of a different FormField). We'd need to change the FormField into a GridFieldComponent probably, or move the title (GridFieldComponent) to be part of the FormField instead of where it is at the moment.

[ScopeyNZ]

Yeah I think there's a search form toggle component that we might be able to leverage if we go for the latter solution (move the title to be part of a React component).