6 second turns

[olanti-p]

The idea has been around for a while: make turns last 6 seconds, like it used to in 0.D (before CleverRaven/Cataclysm-DDA#30253 )

Pros:

• Slows down player progression relative to in-game time (less turns - less opportunity to do stuff in a day)
• Makes some actions more realistic (e.g. walking from one city to another takes several hours instead of under a hour)
• Increases difficulty (faster time progression means hunger/thirst/evolution timers progress faster relative to player actions)
• Mitigates some performance problems (long actions need to process 6 times less turns)

Cons:

• Such a big change will undoubtedly cause bugs that will need fixing
• Makes some actions less realistic and more "gamey" (e.g. walking around a car may consume a minute of in-game time)
• 6 second turns don't look as neat as 1 second turns

Possible alternative is to make turn length configurable, but that'd guarantee even more bugs and a maintenance overhead down the line.

[olanti-p]

Continued in part 2: #2263