Fix OnyxGlobalFAB covering OnyxBottomBar

[JoCa96]

Why?

The positioning of the OnyxGlobalFAB is covering the OnyxBottomBar:
See https://demo-internal.onyx.schwarz/forms

Acceptance criteria

• The OnyxGlobalFAB doesn't cover the bottom bar, if there is one

Implementation details

• Adding a bottombar slot to the OnyxAppLayout

  • only has height when it has content

• Use position: absolute instead of position: fixed for positioning OnyxGlobalFAB. Move OnyxGlobalFAB into the onyx-app__page div in the OnyxAppLayout.vue component

• OR Use CSS to check for the existent of the bottombar slot and increase bottom distance accordingly

DEV handover checklist

Storybook

DEV handover done with: @ADD_DEV_NAME_HERE

Testing

• covered by visual screenshot tests
• covered by functional tests (Playwright or unit test)

Documentation

• auto-generated Storybook code snippets are checked
• component status has been updated in the docs overview
• updated version is released
• updated documentation is deployed

Other

• follow-up tickets were created if necessary (add links below)

UX handover checklist

UX handover done with: @ADD_UX_NAME_HERE

Naming is aligned with Figma

• component name
• which support components are used and how they are named
• all property names and types

Implementation is checked

• all features of Figma are implemented or a follow-up ticket is refine

Other

• follow-up tickets were created if necessary (add links below)