Detach Library loading from Render thread
In scenarios where the library takes a long amount of time to load, the application would become locked up and unresponsive, as library loading was blocking. By detaching library loading to its own thread, the program remains responsive even while the library is loading.
Eventually, a ProgressWidget should probably be added, but that would require a signifigant change to the logic of lib.open_library.
Don't worry about the Pyside app test failing for now (its a bug that is fixed now). But if you want to you can fix it by pulling the changes from the main branch and merging it into yours.
Closing as this seems to have been solved more eloquently in SQL migration