Improve SoftBody user experience

[Mikeysax]

I think the UX of the SoftBody node could be refactor'd to allow the following:

• Inclusive or exclusive pinning of all attachment points. The default behavior would be that all points would be pinned by default so you can exclude certain points.
• Group assignment of attached points to a Bone attachment, as to improve UX. It's very tedious to go through each attached point to set a Bone attachment.
• Painting for selecting attachment points to improve UX

I think ultimately, a better UX as an example would be how Unreal Engine allows you to utilize and make parts of a mesh more cloth-like; if my suggestions don't make 100% sense, maybe the SoftBody node isnt what should be modified; maybe some other Node would work to achieve more cloth-like features on a character mesh.