Config: Change syntax and updates all configs

[mwestphal]

Change config file syntax to:

[
{
  "options": 
  {
    "filename": true,
    "camera-direction": "-1,-0.5,-1",
    "hdri-ambient": true,
    "translucency-support": true,
    "animation-progress": true
  }
},
{
  "match": ".*obj",
  "options": 
  {
    "axis": true,
    "tone-mapping": true
  }
}
]

also adds a test and updates doc

Later:

Add config file control for interactions: #1740
Add glob support in config files: Create issue
Add complete interaction doc: Another PR
Add command-script option: #1734
Reenable test with command script: Another PR

[Meakk]

lgtm

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.70%. Comparing base (f3d7627) to head (8d95329).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1730      +/-   ##
==========================================
- Coverage   96.97%   95.70%   -1.28%     
==========================================
  Files         110      118       +8     
  Lines        8872     9335     +463     
==========================================
+ Hits         8604     8934     +330     
- Misses        268      401     +133     

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