New feature: GPU Picking

[roland]

GPU Multipicking added:

GPU multi picking

A function called multiPickAsync has been added. It’s similar to the pickAsync function but accepts an array of IVector2Like coordinates as an input not just a single one. DOCS: Babylon.js docs (After the PR for the docs gets merged: Update picking_collisions.md by RolandCsibrei · Pull Request #1187 · BabylonJS/Documentation · GitHub)