Analytical_Engine + Graphics_Engine: Re-consider the project graph to dependency diagram method

#### Description:
Current graph projection method involves some redundant steps and results in `RepresentationFragments` attached to a clone of the original graph.
Suggestion is to re-consider this approach and prototype an apporach that simply returns a collection of BHoM representation objects - no graph.

Consider a `IRepresentation` interface to be implemented by concrete representation objects that can be represented in any UI.

Proposal is to prototype:
Text representation object - font, 3d position / orientation, text, height
Geometry representation - geometry, colour