Generate "To Be Bought" List BoM View

[jmwright]

• Always from whatever component level you’re at, recursively combine all the way down through the component hierarchy.
• All into one sheet, made up of all grand totals.
• Singular view of the entire project.
• Takes quantities into account per item.
• Manufacturer part number, but not vendor part number, because we’re not focusing on purchasing it yet.
• The only things that should show up are COTS things.
• Will force a solution to handling items like extruded aluminum, filament, lumber, etc.

[m30-jrs]

DOF use case about purchase lists - https://github.com/Mach30/dof/blob/master/use-cases/07-Generate-project-level-purchase-list-from-BoM-data.adoc