TODO
 - ProjectLibrary Save/Load - saves/loads the hierarchy of ResourceEntries
    - ResourceManifest needs to store relative locations when I save it, so that user can move Project folder safely
 - Resource import queue (ability to display progress bar for resources that are importing)
 - Implement Delete command for ResourceTreeView

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Test:
 - Save/Load (After it is implemented)
     - Ensure that leaving application and then reloading will still recognize previously saved assets and will not reimport them
       - Also ensure that UUIDs will be properly read from .meta files

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LOW PRIORITY

What happens when importer fails importing a file?
 - This can be one of the lasts steps, but I will likely need to go through all importers manually and set them up so they return proper error codes
    and clean up properly on error.
	- In fact they should use exceptions but those should be translated to error codes when returned to Importer
	  - OR just write directly to debug log?
	   - Probably log and error code, since I will need to inform the outside world that import failed somehow