Adding type hints to the code

[XDRAGON2002]

Although static declarations are present in the codebase, it is not uniform throughout.
This issue aims to get the entire project typed, so as to allow mypy enforcement in the future.
I believe working on this issue will help anyone trying to familiarize themselves to the project structure (also helps with easy and friendly PRs)

cve_bin_tool/version_signature.py
cve_bin_tool/version_scanner.py
cve_bin_tool/util.py
cve_bin_tool/cvedb.py
cve_bin_tool/csv2cve.py
cve_bin_tool/file.py
cve_bin_tool/strings.py

These are some of the places which would serve as good starting points.
Also there might be more places where typing needs to be added, that I might have missed here, feel free to open a PR for them as well.

[XDRAGON2002]

Roping in @terriko for verification of issue and adding of "good-first-issue/beginner/easy" issue tag for visibility.

[terriko]

We actually already have a similar open issue that has the flags:

• related Add type hints #761

But in the interest of making this easy for folk to find at the top of the latest issue list, I'm going to leave them both and put the correct tags on this one.

[attreyee-muk]

@terriko can I work on this issue? I am a beginner.

[gaurav879]

I would like to work on this issue.