Add additional models

This project becomes more and more useful with the amount of models trainable or available (pre-trained):

- [x] CopyLastFrame baseline
- [ ] LSTM -> revise implementation
- [x] ConvLSTM -> revise implementation to match original paper
- [ ] U-Net with temporal convolutions
- [x] PhyDNet -> revise implementation to match original paper
- [x] ST-LSTM/PredRNN(++) -> revise implementation to match PredRNNV2 paper (https://github.com/thuml/predrnn-pytorch)
- [ ] Noether Networks (https://github.com/dylandoblar/noether-networks)
- [x] SVG (https://github.com/edenton/svg)
- [ ] MIM (https://github.com/Yunbo426/MIM, PyTorch: https://github.com/bugsuse/MIM_PyTorch)
- [ ] E3D-LSTM (https://github.com/google/e3d_lstm, PyTorch: https://github.com/metrofun/E3D-LSTM)
- [ ] SAVP (https://github.com/alexlee-gk/video_prediction)
- [ ] LFDTN (https://github.com/AIS-Bonn/Local_Freq_Transformer_Net)
- [ ] ...