JetBrains: Manually emit window closing/open events to fix third-party modules that rely on those to render overlays

Created by: philipp-spiess

Closes #36479 (closed)

Manually emit WINDOW_OPENED and WINDOW_CLOSING events if we change the visibility of the Sourcegraph popup. This works around issues with third-party extensions like the material UI theme that uses these events to display overlays.

Test plan

https://user-images.githubusercontent.com/458591/172343541-0701fa2c-687d-4d5e-af92-1ef2c6ef1f01.mov

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.