text: Title: filterform still queries for last field of Basemodel
  Body: ```
  class FilterForm(pydantic.BaseModel):
      city: str | None = Field(json_schema_extra={'search_url': '/api/forms/search', 'placeholder': 'Filter by City...'})
      country: str  | None = Field(json_schema_extra={'search_url': '/api/forms/search', 'placeholder': 'Filter by Country...'})
  
  @router.get('/cities', response_model=FastUI, response_model_exclude_none=True)
  def cities_view(page: int = 1, country: str | None = None, city: str | None = None) -> list[AnyComponent]:
      print(city,country)
  ```
      
  If I change this section of the demo , annotating city and country as optional. Then the selection in webserver queries for country still when clearing the form. Shouldn't go back to http://127.0.0.1:8000/table/cities instead ?
  
  
  
  <img width="1355" alt="Screenshot 2024-03-01 at 11 10 54 PM" src="https://github.com/pydantic/FastUI/assets/30285349/50901223-60e2-4b02-af8d-36061e476aab">
  <img width="1353" alt="Screenshot 2024-03-01 at 11 11 42 PM" src="https://github.com/pydantic/FastUI/assets/30285349/7e058395-5b6f-43eb-a8da-2d15f469616e">
  