WIP: Business Template V2

This is the first step on moving the existing bt5(s) to only use paths, property and patch items.

Documentation (PathItem and PropertyItem )

• https://www.erp5.com/erp5.Design.Business.Template.Specification (Updated)
• https://www.erp5.com/erp5-Business.Configuration.Design (Initial)

Documentation (PatchItem)

• explanation-patch.txt

BusinessPatchItem only supports deepdiff for now as we want to have conflict free and commutative diff system.