deprecate hand_on_leg and hands_on_legs

BUR #43068 has been approved by @nonamethanks.

deprecate hand_on_leg
deprecate hands_on_legs

People should be using any of these instead:

• hand on own leg
• hand on another's leg
• hands on own leg
• hands on own legs
• hands on another's leg

BUR #43070 has been rejected.

create alias hands_on_own_leg -> hands_on_own_legs

And I want to get a vote on this, is it important enough to keep a distinction between "a character having both of their hands on one of their legs" vs "a character having both of their hands on both of their legs, one hand on each leg"? In which case no hands on another's legs tag currently exists for "a character having both of their hands on both of another character's legs, one hand on each leg".

The bulk update request #43068 (forum #363609) has been approved by @nonamethanks.

The bulk update request #43070 (forum #363612) has been rejected by @nonamethanks.