Generate dbt_yml_files from pydantic classes

[aliceliu]

Generated pydantic classes from existing jsonschema using datamodel-codegen --input /Users/alicejliu/git/dbt-jsonschema/schemas/latest/dbt_yml_files-latest.json --input-file-type jsonschema --output model.py --output-model-type=pydantic_v2.BaseModel --target-python-version=3.11 --use-title-as-name --field-constraints

However there are if/then/not statements in the jsonschema that cannot be translated to Pydantic. For those I manually fixed them:

• Created ExpectDict, ExpectCSV, ExpectSQL to handle differences in expect fields
• Created OwnerWithEmail and OwnerWithName to handle oneOf email/name being required
• Created SimpleMetric, DerivedMetric, CumulativeMetric, ConversionMetric, RatioMetric to handle differences in type_params

There were also a couple of other manual fixes I had to make:

• A typing error where FreshnessDefinition was using Any instead of None
• Use Calculation.conversion_rate for default value instead of "conversion_rate"

[joellabes]

Closing in favor of #159