Add Post_model_load, post_lora_load, post_train, post_train_unload function calls (#2539)

* Update train.py

add post_model_load and post_lora_load model calss.

* Update train.py

add post_train and post_train_unload function calls

* Update train.py

* Update base.py

* Update train.py

* chore: lint

* clarify plugin hooks

* Update src/axolotl/integrations/base.py

Co-authored-by: Dan Saunders <danjsaund@gmail.com>

* Update src/axolotl/utils/models.py

Co-authored-by: Dan Saunders <danjsaund@gmail.com>

* Update src/axolotl/utils/models.py

Co-authored-by: Dan Saunders <danjsaund@gmail.com>

* Update src/axolotl/integrations/base.py

Co-authored-by: Dan Saunders <danjsaund@gmail.com>

* Update models.py

* Update models.py

* remove extra call to post_model_load

* chore: lint

* add test for hooks and gc trainer

* disable duplicated code check for test

* fix the path and add better handling

---------

Co-authored-by: Wing Lian <wing@axolotl.ai>
Co-authored-by: Dan Saunders <danjsaund@gmail.com>

tests/e2e/test_lora_llama.py

@@ -48,13 +48,13 @@ class TestLoraLlama(unittest.TestCase):
                     },
                 ],
                 "num_epochs": 1,
-                "micro_batch_size": 8,
+                "micro_batch_size": 2,
                 "gradient_accumulation_steps": 1,
                 "output_dir": temp_dir,
                 "learning_rate": 0.00001,
                 "optimizer": "adamw_torch_fused",
                 "lr_scheduler": "cosine",
-                "max_steps": 20,
+                "max_steps": 5,
             }
         )