[23.0] Fix tool bar on top of pop-ups

[ElectronicBlueberry]

Fixes #15822 by increasing the z-index in default and demo webhooks

How to test the changes?

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• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

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