some small bugs with the example project

[hannesdelbeke]

Hi, I love your project. 💖 It's amazing and will help me so much.

I came across some small bugs while using the example project from this repo:
(i removed the circle node, everything else is the same)

• when alt tab from node editor widget to my IDE, and alt tab back. the alt key is stuck in the node editor.
  e.g. when i MMB + move my mouse, it zooms instead of pans.
  this dissapears when I press Alt again
  100% repro
  other keys also get stuck. e.g. hold CTRL in the node editor. click on another window to make that window active. (e.g. your IDE)
  now alt tab back to the node editor. notice the CTRL key is stuck (and the UI shows the CTRL key is pressed down with the message CTRL: Deselect Nodes following your mouse

• tab brings up the node search context menu.
  but node search doesn't work when launched from the LMB context menu
  nothing happens when clicked.
  100% repro

• auto layout upstream. this seems to not work correctly when selecting everything in the example project. (including the backdrop)
  100% repro

• the default startup layout doesn't seem right.
  
  i would expect something like this instead , where the backdrop fits nicely around the nodes. believe this might be related to auto layout?
  

• clear session message popup is hard to read
  

(i am on windows 11. using python 3.10.5 with PySide2)

[jchanvfx]

one of the bugs relates to this issue #261