Add SimpleCov threshold support

Task 13294
Task 13362
Revise test descriptions, formatting

Task 13294
Task 13362
Fix metric_fu configuration

Task 13294
Task 13362
Fix duplicate method call critiques; revise formatting

Task 13294
Task 13362
Handle uncommunicative variable name critique

Task 13294
Task 13362
Handle line length critiques; revise formatting

Task 13294
Task 13362
Adjust SimpleCov threshold

Task 13294
Task 13362
Add metric_fu results

Task 13294
Task 13362