[REQ] [python-fastapi] Need support for generating Strict Types in pydantic models as part of python-fastapi generator

Created by: puneetugru

Is your feature request related to a problem? Please describe.

As part of the python-fastapi generator, the generated models inherit from the pydantic BaseModel class.

But, the data types used in the generated models currently support basic types and not Strict Types.

Due to this, as mentioned in this issue, pydantic will try to parse values into the shape specified by the model, including coercing the types.

Describe the solution you'd like

The openapi-generator can add an option to the python-fastapi generator, where the generated models will use Strict Types, instead of plain types.

Describe alternatives you've considered

Currently, the generated models need to be edited manually to convert from Types to Strict Types.