plugins XEP-0300, XEP-0446, XEP-0447, XEP0448 and others: Refactoring to use Pydantic: Pydantic models are used more and more in Libervia, for the bridge API, and also to convert `domish.Element` to internal representation. Type hints have also been added in many places. rel 453

from typing import Optional

from twisted.words.xish import domish


class BaseError(Exception):
    namespace: str
    condition: str
    text: Optional[str]
    textLang: Optional[str]
    appCondition: Optional[domish.Element]

class StanzaError(BaseError):
    ...