Qualification tool: Report nested complex types in Potential Problems and improve write csv identification.

[nartal1]

This partially addresses NVIDIA/spark-rapids-tools#814 . Out of 3 tasks in the issue, this PR addresses 2.

1. Report nested complex types in potential problems. Updated existing tests.
2. Removed the hardcode of csv write format. Instead we are checking if the format != TypeSig.none. Running mvn verify did not update supportedDataSource.csv. Hence it does the same functionality without hardcoding. And later if we support csv write then we don't have to update the code here.
3. Write format score is not reported as we might need further discussion on scoring in general.

[nartal1]

build

[tgravescs]

we should also update the docs to explain this and perhaps say if you see this go look at what type it is in other field.

[tgravescs]

build