Cutscenes

Added basic 'cutscene' functionality, though most of it isn't fully
functional.

+ Added CutsceneTrigger prefabs
+ Added logic for cutscenes - player will be moved by self, HUD
disappears, etc.

~ Renamed 'NPC Destination' to 'Destination' because Player cutscene
movement now uses them as well

- Known bug: The player's movement bugs out when approaching the latest
point. Unknown reason - it is apparently detecting the floor in the
collision check.