Cleanup the compiler warnings that GitHub generates

[SteveMaier-IRT]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Github is generating warnings for many things in the code base, even for files that do not change. Go over all of the warnings and clean up the code to remove these warnings. You can see the warnings in the PR link below.

https://github.com/microsoft/electionguard-cpp/pull/306/files

Expected Behavior

Github will continue to add things that are problem, but we need to get code base to compile cleaner.

Steps To Reproduce

No response

Environment

- OS:

Anything else?

No response

[MatthewRatzell]

Feel free to assign this to me, Ill be able to chip away at it over the week