Add new entity and item definitions, refactor related code

- Introduced new CSV files for entities and items, defining various properties and characteristics.
- Refactored the stage.gd script to handle item selection and descriptions instead of entities.
- Updated item button script to reflect changes in item properties and signals.
- Created a new entity.gd script to define the OwniverseEntity class with initialization and parsing methods.
- Modified owniverse.gd to initialize entities from the new definitions.
- Adjusted versioning in export presets and project files to reflect recent changes.

world/entity.gd.uid

@@ -0,0 +1 @@
+uid://tvj1grut2p4x