Set selection also on mouseout

This ensures the selection is set if a selection is initiated inside the
editable but the mouse is moved outside of it before it's released.
Implement URL picker in the editor
Rewrite toolbar formatting button logic
Retrieve the selection when needed instead of saving it on event
Replace lede markup paragraphs with span elements
Add more formatting button guards
Reset selection after formatting text
Handle selection/range correctly for URL picker
Merge branch 'selection' into apply-url-picker
Use correct cancel callback reference
Remove unnecessary empty option

We want the select to default to the first item.
Use URLPicker lib for the table widget
Merge branch 'apply-url-picker'