[Delivers #47583321] Less mouse clicks

Replace all dropdown "Add blah" buttons with a single click button that invokes a blank template changeable based on the 'type' on offer e.g. Add Note shows a template selector with drop down Note Type; changing the Note Type dropdown will load the respective form.

Also removed the drop down menus from the tree widget, replacing "Add Child" with a single click "Add Component" and "+1" with "Add Sibling".

To help with the flow of data-entry, I've added a '+' link at the bottom of the subrecord panel that becomes visible when the subrecord is hovered or focused. This new '+' button enables quick addition of a new sub record form without requiring the user to scroll back to the section heading.