Add Sub-Level Spatial Volume API for Moving Block Structures

To enable complex mechanical contraptions, moving vehicles, and physics-based structures in Bedrock Edition (similar to Java mods like Sable or Create), Add-on creators need a native API for Dynamic Spatial Volumes (Sub-Levels). Currently, moving block assemblies are limited to single custom entities or rigid structure loads, which limits performance and breaks block interactions. Proposed Add-on API Expansion: - Allow creators to group dynamic block collections into an isolated coordinate frame (sub-level). - Provide script controls (`@minecraft/server`) to rotate, translate, and accelerate these volumes smoothly in real time. - Retain internal block states, redstone signals, and container data (chests/hoppers) while the structure moves. - Allow entities and players to stand, ride, and move inside these dynamic sub-levels naturally. This addition would open up immense possibilities for vehicle add-ons, moving airships, elevators, and custom mechanical systems on Bedrock Edition without sacrificing performance.