Data loader refactor (#2707)

* data loading refactor (wip)

* updates

* progress

* pytest

* pytest fix

* lint

* zero_first -> filelock, more simplifications

* small simplification

* import change

* nit

* lint

* simplify dedup

* couldnt resist

* review comments WIP

* continued wip

* minor changes

* fix; remove contrived test

* further refactor

* set default seed in pydantic config

* lint

* continued simplication

* lint

* renaming and nits

* filelock tests

* fix

* fix

* lint

* remove nullable arg

* remove unnecessary code

* moving dataset save fn to shared module

* remove debug print

* matching var naming

* fn name change

* coderabbit comments

* naming nit

* fix test

tests/e2e/integrations/test_hooks.py

@@ -5,7 +5,6 @@ e2e tests to make sure all the hooks are fired on the plugin
 import os
 from pathlib import Path
 
-from axolotl.cli.args import TrainerCliArgs
 from axolotl.common.datasets import load_datasets
 from axolotl.integrations.base import BasePlugin
 from axolotl.train import train
@@ -160,8 +159,7 @@ class TestPluginHooks:
         cfg = validate_config(cfg)
         prepare_plugins(cfg)
         normalize_config(cfg)
-        cli_args = TrainerCliArgs()
-        dataset_meta = load_datasets(cfg=cfg, cli_args=cli_args)
+        dataset_meta = load_datasets(cfg=cfg)
 
         train(cfg=cfg, dataset_meta=dataset_meta)
         check_model_output_exists(temp_dir, cfg)