Description

add repr to serializers, models and services classes, str to serializers,

Clean up test suite to provide consistency, use parameterization instead of loops, misc

use shorthands instead of verbose if-else statements in code base for readability

Issue ticket number and link

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Other Stuff