Add a new renderer API

Goals:

• Extensibility: we need to be able to add new params to the calls to render a texture/rect. For instance we'll need to add fences to the render texture operation for explicit sync purposes.
• No implicit state: no more bind_buffer, begin, end.
• No matrices: these hurt Pixman and we don't need them.
• Clip regions for optimized damage repainting.

Closes: #3188 (closed)

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It was about time we broke that API.