MockTextSurface content renderer UI element.

[kwilliams1987]

Render (as close as possible) the expected output of the text or sprite bank content of the IMyTextSurface.

Implementing internal script rendering is less important as these are not controllable by Programmable Blocks. Perhaps just a placeholder to indicate we expect a script output.

Once it's available for a single IMyTextSurface (LCD) then implement a selector for IMyTextSurfaceProvider.