Write Render Mesh Method + Shader

Implement the RenderMesh method, either as part of the main Renderer class or as a separate MeshRenderer class (this class can then also be responsible for related set-up and tear-down operations, keeping a list of things that need to be rendered, and so on).

The mesh rendering procedure should take in a Mesh asset along with a set of instance-specific attributes like the root world space matrix, any game-specific color transformations that have to be done to the model (ie. team-specific colors for the albedo texture), and so on. The object that describes a renderable mesh should simply be called RenderableMesh, in the same way that we have a RenderableSprite for UI elements, and should encompass all the properties needed to fully render a mesh.

The corresponding shaders should also be named Mesh and should take in the standard material definition along with the per-object values, as specified within the RenderableMesh object.

Lastly, Skeletal Animation is not a direct part of this, but RenderableMesh will be expanded to also house a set of bone matrices that are passed down to the shader. The shader will have a compile-time branching operation to either perform a normal transformation, or to use bone matrices instead.