Clean up `setter and getter tests`

# Description
Some `getters and setter tests`  have unneeded variables or have unneeded `copy.deepy_copy` variables that can be removed to be simpler to read, understand, and maintain. 

## Examples:
* [ ] `test_process_getters_and_setters`

Some have unneeded fixtures in the test parameters that can be removed to be simpler and better.

## Examples
* [ ] `test_complex_process_node`