* closes#133
* fix(gltf_auto_export): corrected ron value for "spawnHere" components
* fix(bevy_components): fixed handling of empty/ unit structs
* updated to/from prop_groups
* updated tests/ expected files
* bumped version
* removed verbose "watching schema file for changes"
* fix(bevy_gltf_components): fixed issue of incorect handling of empty component values in non legacy mode:
* aka: replacing empty component values (ron strings) with '()' should ONLY happen in legacy mode
* even more aka: ron strings for component values should not be altered when not in legacy mode (provided ron
strings should be valid)
* tests():
* changed bevy_component tests to use testing/bevy_example as source for registry data
* removed testing/bevy_registry_export, as it is redudant
* related tweaks & cleanups
* chore(crates): bumped up versions because of breaking change
* chore(examples): updated registry export example to use up-to-date / fixed components data
* chore(bevy_gltf_components): added back warning about legacy mode, in a less spammy way
* docs(bevy_components): added notes about v0.3 breaking changes
* 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
