Segmentation Metrics

[jhabr]

This PR adds the calculation of several segmentation metrics. It's based on this repo.

Note that there seems to be a bug in the calculation that needs to be addressed.

TODO: Write test for tp, tn, fp, fn.

This is the API to use (model independent):

from utils.metrics import Metrics

metrics = Metrics().calculate_batch(
    masks=test_masks,
    predicted_masks=predicted_masks
)

print(metrics)

[jhabr]

Disitinguish between false negatives and false positives.

[jhabr]

Implement here...