DepthOfFieldNode: New implementation. (#31547)

* Manual MRT test.

* DepthOfFieldNode: Fix MRT setup.

* DepthOfFieldNode: Initial approach.

* DepthOfFieldNode: Fix kernel size.

* DepthOfFieldNode: Clean up.

* DepthOfFieldNode: Fix aliased near field edges.

* DepthOfField: Clean up.

* DepthOfFieldNode: Add comments.

* DepthOfFieldNode: Final adjustments.

* E2E: Update screenshot.

* DepthOfFieldNode: Clean up.

* DepthOfFieldNode: Clean up.

* Examples: Use `OrbitControls` in DOF demo.

Author: Mugen87