Addon Manager: Rework backend to use package.xml
This shifts to use the model-view-controller pattern for the list of addons, and moves to using a full model class rather than an indexed array for the data storage and management. This enables much more information to be stored as part of the new AddonManagerRepo data type. It now wraps the Macro class for macros, supports Preference Packs, and provides access to the Metadata object.
This commit is contained in: