Random scenario selection options

Add two options in the World Defaults menu to enable random scenario selection for random characters.

Options:
- Random character and scenario  
- No challenges

This PR is a follow up to https://github.com/CleverRaven/Cataclysm-DDA/pull/9696.
When the random scenario selected earns points, these points are added by this line to be used in the rest of the automatic random character generation. When this happens characters can get higher stats, more positive traits or more skills.