* refactor one_cycle lr scheduler so it's reusable in more situations
* fix validation for lr_scheduler
* default to cosine anneal strategy
* one cycle lr exepects cos
* WIP conversion to use pydantic for config validation
* wip, more fields, add capabilities
* wip
* update pydantic validation to match existing tests
* tweak requirements
* setup deprecated paams pydantic model
* more validations
* wrap up rest of the validations
* flesh out the rest of the options from the readme into pydantic
* fix model validators as class methods
remember to return in validator
missing return
add missing relora attributes
fix test for DictDefault change
fix sys template for mistral from fastchat change in PR 2872
fix test for batch size warning
* more missing attributes for cfg
* updates from PR feedback
* fix validation for datasets and pretrain datasets
* fix test for lora check
