GeezerVison

Closes #384

• Adds a new fpl.utils/gui module where the GUI selection is handled and nothing else.
• Fastplotlib lists its own GUI preference order, but respects users who override it.
• Avoid importing multiple GUI libraries.
  • This makes fpl lighter.
  • In my experience importing multiple GUI frameworks can also result in odd bugs.
  • Remove all imports of wgpu.gui.auto except in fpl.utils.gui.
  • Users can still use a custom canvas and thus mix GUI toolkits if they want to go crazy :)
• The fpl.run() method now matches the GUI backend in use (this was not necessarily the case previously).
• Support for all modern Qt libraries!
• The cases where ipywidgets is imported is now conditional (only happens in Jupyter notebook / lab).

Note on performance: The import time is about 0.2 s faster on desktop (because it does not import Jupyter stuff). In the notebook we can expect a similar improvement because glfw and qt are not imported by default (when available).