Shortened widget run in `__main__`

[PrimozGodec]

Issue

Widgets have complicated part of the script for running widget directly and it is not working since the dataset is missing

Description of changes

Simplifying running the widgets with WidgetPreview

Includes

• [X] Code changes
• [ ] Tests
• [ ] Documentation

[codecov[bot]]

Codecov Report

Merging #157 into master will increase coverage by 0.53%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #157      +/-   ##
==========================================
+ Coverage   58.91%   59.44%   +0.53%     
==========================================
  Files          13       13              
  Lines        3315     3282      -33     
  Branches      491      488       -3     
==========================================
- Hits         1953     1951       -2     
+ Misses       1227     1196      -31     
  Partials      135      135