Move some get funcs from Vec3 to Mat4.
Move some get funcs from Vec3 to Mat4.

--HG--
branch : feature/math-objects

horryq/engine-1,3DGEOM/engine,SuperStarPL/engine,sanyaade-teachings/engine,H1Gdev/engine,playcanvas/engine,horryq/engine-1,shinate/engine,nizihabi/engine,sanyaade-teachings/engine,RainsSoft/engine,RainsSoft/engine,playcanvas/engine,sanyaade-teachings/engine,nizihabi/engine,SuperStarPL/engine,shinate/engine,aidinabedi/playcanvas-engine,RainsSoft/engine,maxwellalive/engine,maxwellalive/engine,guycalledfrank/engine,horryq/engine-1,nizihabi/engine,3DGEOM/engine,maxwellalive/engine,MicroWorldwide/PlayCanvas,sereepap2029/playcanvas,guycalledfrank/engine,SuperStarPL/engine,3DGEOM/engine,aidinabedi/playcanvas-engine,H1Gdev/engine,MicroWorldwide/PlayCanvas,sereepap2029/playcanvas,sereepap2029/playcanvas,shinate/engine