[mednet.tests] Move tests to single directory

tests/classification/test_tbpoc.py

tests/classification/test_tbx11k.py

tests/classification/test_visceral.py

tests/common/__init__.py

tests/common/conftest.py

tests/common/data/16bits.png

tests/common/data/iris-test.csv

tests/common/data/iris-train.csv

tests/common/data/iris.json

tests/common/data/raw_with_black_border.png

tests/common/data/raw_with_elastic_deformation.png

tests/common/data/raw_without_black_border.png

tests/common/data/raw_without_elastic_deformation.png

tests/common/test_database_split.py

tests/common/test_image_utils.py

tests/common/test_resource_monitor.py

tests/common/test_transforms.py

tests/segmentation/__init__.py

tests/segmentation/conftest.py

...ams/models/histograms_lwnet_chasedb1_first_annotator.json