"Expert" import mode

[jsl12]

Needed to make all the app importing/reloading work with packages in addition to just modules.

Change overview:

• Reworked AppManagement.check_app_updates, primarily by splitting into sub functions.
  • Reloading packages properly after file changes depends on utils.recursive_reload
• Added some type hints around
• Converted some dictionaries being passed around to dataclasses for ease of use in IDEs.