Add scientists to starting area

[jakeHaasBlog]

We decided that we should add scientist npc's in the starting area to explain plot points and lore. They will also make the world seem less empty.

• [x] Add prefab for scientist
• [x] Add a few sprite images for their bodies
• [x] Add modifiable text strings (array that is cycled through)
• [x] Scientists show interact button when the player is close enough
• [x] Text is displayed on screen when interacted with
• [x] Place scientists in the starting world (will have to unload them when new world is loaded)
• [x] Scientists can't be walked through

[jakeHaasBlog]

Note: when adding a new scientist, the player's script needs them as an input. Note: scientists must be in the 'scientists' game object. Otherwise they won't disappear outside of starting world