[feature request] Please add center line dice score to the evaluation pkg

[neuronflow]

Please do add center line dice score to the evaluation pkg. described here: https://arxiv.org/abs/2003.07311

We came up with this probably very inefficient implementation (not tested):

from skimage.morphology import skeletonize, skeletonize_3d
​
class ClDice(INumpyArrayMetric):
    """
    Represents the clDice Metric as defined in: https://arxiv.org/abs/2003.07311
    
    """
​
    def __init__(self, metric: str = 'CLDICE'):
        """Initializes a new instance of the DiceCoefficient class.
        Args:
            metric (str): The identification string of the metric.
        """
        super().__init__(metric)
​
    def calculate(self):
        """Calculates the clDice coefficient."""
​
        gt = self.ground_truth
        seg = self.segmentation
        
        gt_cl = skeletonize_3d(gt)
        seg_cl = skeletonize_3d(seg)
        
​
        cl_sc_rec = (np.sum(seg*gt_cl)*1.0)/(np.sum(seg*gt_cl)*1.0)
        cl_sc_prec = (np.sum(gt*seg_cl)*1.0)/(np.sum(gt*seg_cl)*1.0)
        
​
        f1_cl = 2*((cl_sc_prec*cl_sc_rec)/(cl_sc_prec+cl_sc_rec))
​
        return f1_cl

Thanks! :7