[tests/classify] Rectify tests depending on the RGB() transform output after upgrade to torchvision 0.18.1

[classify.scripts.saliency] Incorporate evaluation code directly on interpretability/completeness analysis; Remove outdated saliency-evaluation script and engine; Fix test units

[evaluation] Homogenize segmentation/classification code; Use more credible constructs (DRY); Fix test units

Revamp tests; Delete outdated; Make common conftest.py; Improve segmentation tests; Allow segmentation tests to run on CI

[libs.segmentation.scripts.evaluate] Only evaluate - leave view to another command; Simplify by using credible package