adodbapi: Simplify simple functions by using assignments and fix misplaced docstrings

[Avasam]

adodbapi version of #2214

[vernondcole]

I'm not sure if this would fulfill the requirements of PEP249 which, if I understand correctly, requires a function here. Maybe it would work right, but feels funny and may be hard to understand.
In any case, the string in the line following the def is a docstring, and if the def is removed then the docstring should become a comment.
@mhammond might weigh in on this.

[Avasam]

As far as the docstring goes, there's still some value statically for variables, even though it doesn't end up in the runtime __doc__.

To keep the same __doc__ as the descriptions in https://peps.python.org/pep-0249/#type-objects-and-constructors , then these changes are not valid for PRP 249 functions.