text: Title: Enhancement: Auto-register factories as pytest fixtures
  Body: It would be super handy to have some method that would easily create a fixture out of a factory. For example:
  
  ```python
  class SomeLongNamedModel(BaseModel):
      id: UUID
  
  
  @register_fixture   # Or some better name?
  class SomeLongNamedModelFactory(ModelFactory):
      """Factory to create SomeLongNameModel instances
      
      Use this factory to generate SomeLongNameModels filled with random data
      """
      __model__ = SomeLongNamedModel
  ```
  
  And then 
  
  ```bash
  $ pytest --fixtures
  
  # other output...
  some_long_named_model_factory
      Factory to create SomeLongNameModel instances
      
      Use this factory to generate SomeLongNameModels filled with random data
  ```
  
  This is following the model of `pytest-factoryboy` which automatically converts the PascalCase class names to be the snake_case equivalent for the fixtures.