[FeatureRequest]: Adding Models Architectures

[innat]

@qubvel Thanks for this great repo. Here is some segmentation model architecture that is worth adding. Please consider adding them to this great repo.

• Unet++ : Code
• DeepLabV3 and DeepLabV3+ : Sample.
• DANet - Sample
• CCNet - Sample

Also, please consider adding

• Auxiliary classification output

[innat]

In the meantime, if anyone who looking for UNet++ (aka, XNet) in tf.keras. Here, XNet-TF.Keras. Discussion.