Summary:
A slight insanity here... I realized I will need to create
`GraphDbAccessor` instance (which need `&GraphDb`) within some members
of `::impl` classes. Within those classes I can pass `this` to those
members, if `this` is a valid `GraphDb`. Semantically it really is (at
the moment), but heirarchically it wasn't. This diff changes that.
`GraphDb` is now only an interface. `PublicBase` is the base for all
the public classes, `PrivateBase` for the `::impl` classes. Seems to
work.
Oh yes, another thing to keep in mind when doing this is that I should avoid
calling virtual functions in public classes (the motivation for the double
heirarchy). Before this diff the getters weren't virtual, now they are, so
I should have made all the appropriate changes in code as well.
Buda, was this a task I could have delegated to you or Cula?
Reviewers: teon.banek, dgleich, buda
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1120