Shortcuts: Execute preventDefault only if keyboard shortcuts are enabled

[Spielboerg]

Related issue #23351

What I did

Currently, on every keyboard event preventDefault() is called. This PR changes this behavior so this is only done if keyboard shortcuts are enabled.

⚠️ Disclaimer: I was not able to generate a sandbox locally with a different config than the default one (I wanted to disable the shortcuts). So I was not able to test if my changes actually work. If you can help me to set up a sandbox with disabled shortcuts I can test it myself, otherwise, I kindly ask if you can test it yourself.

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[kasperpeulen]

LGTM, thanks!