Started support for editor view.
Moved comment elements to be added relative to content area instad of
specific target reference element.
Added relocating on screen size change.
Intended to fix positioning quirks caused by changing codemirror
instance size when you have lines that wrap and cause line height
changes. Often caused by editor toolbox expand/collapse.
This adds a debounced resize observer to refresh editor layout on size
change.
Also tweaks toolbox expand/collapse to more consistently set aria
attribute.
For #3186
