[Enhancement] Tab-navigation, align styling.

[x] I have written a good issue

Describe the enhancement

Today there is misalignment between tab-content (items) width/margin and divider width/margin at breakpoint (768).

Describe the solution you'd like

Adjust styling so that the divider has the same width/margin as the tab-content (items) at breakpoint 768. When in scroll state the divider width is edge - edge but content has page margin (AS-IS)

Have you considered any alternatives?

Are there any additional context?

Tab-nav-width-768

Checklist:

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Refinement

[ ] Request that the issue is UX refined
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Implementation

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[ ] Make sure you have read: "Before you get coding".
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[ ] Create a branch from the develop branch following our branch naming convention.
[ ] Publish a WIP implementation to Github as a draft PR and ask for feedback.
[ ] Make sure you have implemented tests following the guidelines in: "The good: Test".
[ ] Update the cookbook with examples and showcases.

Review

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[ ] Create a pull-request. If you created a draft PR during implementation you can just mark that as "ready for review".

kirbydesign / designsystem