Fixes https://gitlab.com/kicad/code/kicad/issues/10136
Also includes a performance improvemnt by caching the 3D model matrices.
Paste layers should be clipped in Realistic mode. Verifying that paste doesn't extend beyond the board area should be left to DRC, or non-realistic mode if you need a 3d view of it. Fixes https://gitlab.com/kicad/code/kicad/issues/9460
There's nothing "legacy" about the OpenGL 3D renderer.