set class names in IStrategy.set_freqai_targets method, also save class name with model meta data

freqtrade/freqai/base_models/PyTorchModelTrainer.py

@@ -1,6 +1,6 @@
 import logging
 from pathlib import Path
-from typing import Dict
+from typing import Any, Dict
 
 import pandas as pd
 import torch
@@ -22,11 +22,13 @@ class PyTorchModelTrainer:
             batch_size: int,
             max_iters: int,
             eval_iters: int,
-            init_model: Dict
+            init_model: Dict,
+            model_meta_data: Dict[str, Any] = {},
     ):
         self.model = model
         self.optimizer = optimizer
         self.criterion = criterion
+        self.model_meta_data = model_meta_data
         self.device = device
         self.max_iters = max_iters
         self.batch_size = batch_size
@@ -126,6 +128,7 @@ class PyTorchModelTrainer:
         torch.save({
             'model_state_dict': self.model.state_dict(),
             'optimizer_state_dict': self.optimizer.state_dict(),
+            'model_meta_data': self.model_meta_data,
         }, path)
 
     def load_from_file(self, path: Path):
@@ -135,4 +138,5 @@ class PyTorchModelTrainer:
     def load_from_checkpoint(self, checkpoint: Dict):
         self.model.load_state_dict(checkpoint['model_state_dict'])
         self.optimizer.load_state_dict(checkpoint['optimizer_state_dict'])
+        self.model_meta_data = checkpoint["model_meta_data"]
         return self