Separate interfaces and platform-specific realizations

[k4G17eYWI]

Intent

It would be great to make interfaces to MonoGame objects (IGraphicDevice, ITexture2D, IContent, etc.) and separate them into a platform-independent Nuget package. Also all data-structures like vectors, matrices, colors, etc. should be put into it.

Motivation

Thus it will be possible to create platform-independent projects instead of using shader-project.

Moreover, this functionality will not break backward compatibility, but will expand the possibilities of creating projects.

[mrhelmut]

Covered by #8242

[k4G17eYWI]

Got it! Naming got me confused a bit.