Use DEFAULTMODE as input context in choose_direction,

And use pause (lowercase) as action for direction (0,0).

Using the DEFAULTMODE context allows the pause action from the normal game mode to be used. Previously it would use the" PAUSE" action from the DIRECTION context, which was not mapped at all.

Fixes https://github.com/CleverRaven/Cataclysm-DDA/pull/7283#issuecomment-40889823