Add alternate frame transport

[ackwell]

Currently, I'm using a DirectX shared texture to transport frame data between the render process and the game. This is, unfortunately, unsupported on linux/wine/dxvk - with no solution in sight.

Look into adding a secondary frame transport method that will work on linux.

Current idea: Transport dirty bitmap rect from render to plugin over shared memory (might need a secondary loop separate from the ipc buffer) - plugin can then use a regular dynamic texture updating with the dirty rects.