* fix(gltf_auto_export): added fix for correct "deep-copying" of objects & hierarchy so that animated
meshes & nested hierarchies get exported correctly
* test(gltf_auto_export):
* added visual testing to check for overall regression :
* added screenshoting in bevy app
* added visual compare with reference screenshot on python side
* added testing of correct export of animated models
* added testing of correct export of empties
* added testing of correct export of nested hierarchies
* added testing of correct export of blueprints, with & without components etc
* fixes#147
* added filtering out of invalid components/ custom properties:
* includes filtering out of invalid / disabled components as defined in bevy_components, components_meta etc
* completely changed handling of "unique" (non blueprint) objects by copying them instead of moving/renaming them & manipulating their custom properties : much cleaner, much simpler !
* disabled default gltf export of optimised animations
* added tests !
* closes#139
* closes#141
* closes#142
* closes#146
* fixed issue with "reload registry" not clearing previous data
* added watcher/ poll system to automatically updated the registry & components list when the registry file has been changed
* BREAKING CHANGE ! changed internal representation of components, incompatible with v0.1, breaks UI values.
* added buttons to regenerate UI to account for/fix the above and to offer the ability to regenerate UI values from custom property values
* lots of cleanups
* added tests
* closes#127
* closes#124
* closes#121
* closes#130
