Decouple loading and "holding" packages from the UI - Creation of PackageLoaders

[marticliment]

• Decouple loading and "storing" packages from the UI. This task will be handled by a new class named PackageLoader, whose task will be loading the packages and handling their lifecycle.
• Transition the navigator into a instanceless, type-driven navigation experience.

Direct consequences of this change:

• Ability to delete UI Pages when not focused without having to reload Packages from the Managers each time. This will allow for deletion of Page Instances when on background and (theoretically) substantially decrease the RAM Usage, as well as the CPU usage.
• Better integration with the API
• Better interop across package pages and package operations.
• Expected better performance for loading Corresponding packages across pages

TODO:

• Fix searching for packages on the Discover Packages tab