Add interaction framework

[DerpyNewbie]

• 2 ways of interaction input
  • Grab
    • Should be basically same as VRCPickup, but with proximity update
  • Trigger
    • Should be used within grabbed object to interact specific parts within it
• Works locally
  • Add optional VRCObjectSync-like component to sync globally
• Local Hands API
  • Provided for callbacks to get more in-depth information about interaction
  • Vector3 Position
  • Quaternion Rotation
  • enum HandType
    • None
    • Left
    • Right
  • bool IsDominant
  • float Trigger
  • bool Grab
  • bool Button1
  • bool Button2
• More callbacks, More customization
  • When controller interaction is available from either of the hand
    • OnInteraction_Enter
    • OnInteraction_Stay
    • OnInteraction_Exit
  • When controller interaction occurred with grab
    • OnInteraction_Grab
    • OnInteraction_GrabbedTriggerDown
    • OnInteraction_GrabbedTriggerStay
    • OnInteraction_GrabbedTriggerUp
    • OnInteraction_Drop
  • When controller interaction occurred with trigger
    • OnInteraction_TriggerDown
    • OnInteraction_TriggerStay
    • OnInteraction_TriggerUp