Same as `nn.BCEWithLogitsLoss`, but flattens input and target.

def BCEWithLogitsFlat(*args, axis:int=-1, floatify:bool=True, **kwargs):
    "Same as `nn.BCEWithLogitsLoss`, but flattens input and target."
    return FlattenedLoss(nn.BCEWithLogitsLoss, *args, axis=axis, floatify=floatify, is_2d=False, **kwargs)