Edge and Sharp tool qualities

[Atermonera]

Brief description of the issue

While implementing tool qualities, I added a tool quality for knives in general to capture the existing use cases. However, this should be refactored to separately cover /obj/item/var/edge and /obj/item/var/sharp separately.

Additional info:

• Server Revision: Found using the "Show Server Revision" verb under the OOC tab.
• Anything else you may wish to add (Location if it's a mapping issue, etc)