Refactor VNDB.py

[Nihilate]

Once the common objects are created, VNDB.py should be cleaned up and made as simple as possible. While it's not possible to utilise the web api, it would be nice to clean up the TCP stuff so that it better reflect the other code (e.g. async)

Goals:

• Reuse the shiny new common code (where possible)
• Return a common object
• Add unit tests
• Add integration tests