* fixed handling of gltf dummy file & settings storage
* experimenting with best approach for settings diffing for auto export
* started (wip) moving out bevy_components settings from registry to indenpendant settings
* minor tweaks
* 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
* this is in preparation for future support in bevy & for more coherence & practicality
* overhauled metadata tooling
* overhauled most of the operators
* overhauled most of the UI
* all the basics & more work !
* unrelated: also started preping for auto_export operator removal
* 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
* improvements to assets ui
* assets ui now specific to per level data, not based on selection anymore
* blueprints ui now presents assets per blueprint
* a lot of tweaks & improvements in the areas above
