Provide the full parsed config file to each plugin

Feature

Provide the full parsed config file to each plugin

Pitch

Currently, Mypy plugins are passed only the Options object in their constructor, which captures Mypy options but not Mypy plugin options. Consequently, each plugins has to re-parse the file. This is a waste of time, may add to the necessary dependencies for a plugin with configuration, and requires re-implementing the logic for parsing different file types (TOML vs config). Here's an example of the pydantic plugin doing just this:

https://github.com/pydantic/pydantic/blob/06448aa41764d0c1e1c2f9455b108c4b21012929/pydantic/v1/mypy.py#L239-L256

The neatest solution would be to pass the full config object to the constructor. Unfortunately, this would be a breaking change to the constructor signature, so probably the more palatable option would be to store the config options within each Plugin instance (in the constructor), which the subclasses can use if they want:

class SomeMypyPlugin(Plugin):
    def __init__(self, options: Options) -> None:
        super().__init__(options)
        my_config_option = self.raw_config["tools"]["some_mypy_plugin"]
        # use my_config_option

Comienza por el constructor de Plugin y la ruta de carga de la configuración; después, compara el ejemplo de plugin de pydantic enlazado en el issue. Traza cómo se analizan actualmente Options y la configuración del plugin, y define la finalización como hacer que toda la configuración analizada esté disponible para las instancias del plugin sin que cada plugin tenga que volver a analizar archivos TOML o de configuración.