Propose a unified VPR framework/class UML

[GabeBolton]

Create a high-level UML diagram to describe the interfaces of the VPR class.

[GabeBolton]

@carson-sky @owenclaxton-QUT When you get a chance, let me know what feedback you have on that commit.

A few initial thoughts could be:

• Is the added 'cleanness' of having VPR.ref and VPR.query as attributes of the VPR class worthwhile when we already should have all the data in the included VPRImageProcessor object, e.g. VPR.vip.IMG_FEATS, VPR.vip.ODOM, etc?
  • If not, should the VPR.set_query_matches method for calculating the true query matches (e.g. based on odometry distance or file index) be moved into VPRImageProcessor?
• Do we want to have a unified Integrity.train() method, or do we anticipate training setup being different enough for each integrity subclass that we would need to rewrite it with different inputs every time?
• Could we just add distance and match calculation into VPRImageProcessor and not have a separate VPR class that subclasses are based on?