CVector refactor

[MiranDMC]

• Reorganized contents of CVector.h
• Separated declarations from implementation
• Unified function names
• All functions are now inlined
• Added vector LERP functions
• Added unit tests project

[gennariarmando]

A refactor sounds nice and all, but in my opinion having multiple implementations for the trilogy for the sake of keeping one constructor call the original game function isn't worth the pain of editing it in the future.

One single CVector class with all the implementations inlined inside one header file shared across the trilogy, with macros to not implement it for IV sounds way more reasonable for such a drastic change.

[MiranDMC]

Removed game specific CVector implementations.
GTA2's CVector.h contained some extra classes. Extracted to CVector2D.h.
Created CVector in shared location. All games are now using the same code.

In future same treatment should be done to the CVector2D, CMatrix etc.