During it's exit transition, Omnibar is still visible when it disappears against dark background

[DigiWorm0]

Environment

• Package version(s): @blueprintjs/select v4.4.1 with @blueprintjs/core v4.5.1
• Operating System: Windows 11 21H2
• Browser name and version: Firefox 102.0.1

Code Sandbox

Minimal Reproduction: Blueprint's own example (Make sure dark-mode is on though)

Steps to reproduce

1. Create an Omnibar
2. Make the page use a dark background
3. Open the Omnibar
4. Close the Omnibar

Actual behavior

When transitioning out, Omnibar gets significantly blurred and then disappears as if it pops out of existence,

Expected behavior

When transitioning out, Omnibar should get significantly blurred then smoothly fade out.

Possible solution

Instead of blurring when trying to fade-out, it should also transition it's opacity.

This issue is probably a bit nit-picky, but from a user's perspective it looks rather strange.

[adidahiya]

Yeah, I can see there's a bit of a white cloud visual "pop" when transitioning out. We'll need to revisit the CSS transitions here. Maybe it's more noticeable now with the darker dark theme colors in Blueprint v4.1+