👼Script: ✨ OGRE Mesh/Material bindings + example

This introduces 'example_ogre_terrnBatcher.as' which shows how Mesh/Material API works and will evolve into a production tool. this will conclude RigsOfRods#3030.

THE INTENDED USE of the future completed TERRN BATCHER:
1. You start with a list of OGRE SceneNodes - see green box.
2. you pick those you want to batch together - see orange box.
3. [WIP] The tool generates one mesh which contains all those picked (keeping position, scale and rotation) and cover them in single material containing all the textures.
4. [TBD] The tool remembers what batches were done as a 'schedule', and allows saving/loading the schedule as file. Modders can share and improve the schedules.
5. [TBD] Modders can launch the tool directly from .terrn2 and auto-execute a schedule on map load.
6. Profit