* coherence pass : "main" scenes & co renamed to "level" scenes & co
* auto export now toggled ON by default, but bailing out early if there are no main & lib scenes added
* UI improvement for adding level/lib scenes
* minor cleanups
* main/library/nothing is now an enumProperty on scenes themselves
* main/library scene listing is a dynamic property of the Blenvy core class instead of CollectionProperties
* this means that removing / renaming scenes using the normal blender workflow automatically changes things for Blenvy as well !
* overhauled & simplified main/library scenes ui accordingly
* same for all the code that needed access to the main/library scenes
* added main/library scene NAMES computed property for convenience
* fixes & experiment to auto export
* added support for "always export" functionality for blueprints & levels
* fixed issues with asset management
* fixed issues with tracker
* more ui improvements (display of the number of assets etc)
* a lot more minor tweaks
* fixed overhauled, cleaned up and improved settings change detection
* serialize_scene now generate a hash per object instead of keeping the details (useless)
* changed handling of gltf settings, so that only the actual non default, changed settings are saved
* a ton of minor changes & cleanups to get export working correctly: it works !
* started adding materials_in_depth_scan (wip) to be able to control more detailed (but costly) materials diffing for change detection
* fixed/ overhauld asset & blueprint scanning
* added polling for blueprints (not 100% sure yet)
* add-on-prefs => settings
* removed the now obsolete auto-export operator & preperences
* a lot of other minor changes
* removed a lot of obsolete code
* overhauled settings upsert
* added save & load of blenvy common settings
* removed most of the specific uis (mostly auto export)
* moved change detection logic out of auto export (wip)
* added helper to compare setting dicts
* cleaned up some incoherent naming
* stripped auto_export of a lot of its internals (wip)
* main settings ui overhaul: now components & auto export provide their own settings UI function
* added correct injection of assets + export path to blueprints
* moved a few common elements to "core" for better reuse
* more tweaks/ experiments with paths handling
* moved & overhauled a few of the blueprint & assets tools
* lots of minor tweaks & changes
