Friendship mechanic added

This update allows employees to become friends, which can improve their team's compatibility and effectiveness, but also increase the impact of losing team members.

Changes

• Added employee friendship mechanic
  
• Added tooltip support for list column headers, used sparingly so far
  
• Adjusted audio positioning so everything isn't as silent when zoomed in
  
• Trait filter in lists can now be filtered by requiring all selected traits instead of just any of them
  
• You can now assign staff to the outside for fixing wind turbines and batteries
  

Fixes

• Fixed only being able to toggle columns with a game loaded
  
• Fixed columns in employee window not properly loading toggle state from save
  
• Fixed bug in calculation that checks whether employees are seated next to each other, which would pass through cubicles in some cases