[REQ][Python-flask] Support type hints

Would it be possible to add support for type hints in python flask generator?
It would help me to reduce the number of bugs in my application.

Ex replace this:

class ConnectionInfo(Model):
    """NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).

    Do not edit the class manually.
    """

    def __init__(self, name=None):  # noqa: E501
        """ConnectionInfo - a model defined in OpenAPI

        :param name: The name of this ConnectionInfo.  # noqa: E501
        :type name: str
        """
        self.openapi_types = {
            'name': str
        }

        self.attribute_map = {
            'name': 'name'
        }

        self.name = name

    @property
    def name(self):
        """Gets the name of this ConnectionInfo.

        Human-readable name of the connection.  # noqa: E501

        :return: The name of this ConnectionInfo.
        :rtype: str
        """
        return self._name

    @name.setter
    def name(self, name):
        """Sets the name of this ConnectionInfo.

        Human-readable name of the connection.  # noqa: E501

        :param name: The name of this ConnectionInfo.
        :type name: str
        """

        self._name = name

with:

class ConnectionInfo(Model):
    """NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).

    Do not edit the class manually.
    """

    def __init__(self, id:str=None, name=None, references=None, db_info=None):  # noqa: E501
        """ConnectionInfo - a model defined in OpenAPI"""
        self.openapi_types = {
            'name': str
        }

        self.attribute_map = {
            'name': 'name'
        }

        self.name = name

    @property
    def name(self) -> str:
        """Gets the name of this ConnectionInfo.
        Human-readable name of the connection."""
        return self._name

    @name.setter
    def name(self, name: str):
        """Sets the name of this ConnectionInfo.
        Human-readable name of the connection. """
        self._name = name

Start by locating the Python Flask generator templates and the tests or sample outputs used for generated model classes. Compare their current output with the type-hinted example in the issue; done means generated models consistently include the requested type annotations without breaking existing output expectations.