Change return types to avoid IDE errors/warnings

[HPRIOR]

Various IDEs complain about the Cursor type not being iterable even though it is.

For example:

def example():
    with connect( user="***", password="***", dsn="***") as connection:
        with connection.cursor() as cursor:
            execute_stmt = cursor.execute("select * from table")
            if execute_stmt:
                return [r for r in execute_stmt]

When using the pyright lsp with neovim, I get this error:

 "Type[Cursor]" is not iterable

When using pycharm I get a warning of:

Expected type 'collections.Iterable', got 'Type[Cursor]' instead 

As temporary work around I have modified the signature of the execute method of Cursor class in oracledb/cursor.py to return Union['Cursor', None] instead of Union[Type["Cursor"], None].

original:

    def execute(self, statement: Union[str, None],
                parameters: Union[list, tuple, dict]=None,
                **keyword_parameters: dict) -> Union[Type["Cursor"], None]:

new:

    def execute(self, statement: Union[str, None],
                parameters: Union[list, tuple, dict]=None,
                **keyword_parameters: dict) -> Union['Cursor', None]:

OS: macOS BigSur v11.6.1
pycharm 2022.1.4 (Professional Edition)
NVIM v0.7.2
pyright 1.1.270

[anthony-tuininga]

Included in python-oracledb 1.1.1 which was just released.