* Modifying solvers to log every epoch correctly
* add `on_epoch` flag to logger
* fix bug in `pinn.py` `pts -> samples` in `_loss_phys`
* add `optimizer_zero_grad()` in garom generator training loop
* modify imports in `callbacks.py`
* fixing tests
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Co-authored-by: Dario Coscia <dariocoscia@dhcp-015.eduroam.sissa.it>
* Solvers for multiple models
- Implementing the possibility to add multiple models for solvers (e.g. GAN)
- Implementing GAROM solver, see https://arxiv.org/abs/2305.15881
- Implementing tests for GAROM solver (cpu only)
- Fixing docs PINNs
- Creating a solver directory, for consistency in the package
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Co-authored-by: Dario Coscia <dariocoscia@dhcp-040.eduroam.sissa.it>
