2537: Add news source filter and logos

[steffenkleinle]

Short Description

Proposed Changes

• Add a toggle button filter group to filter between all, local and national news
• Remove the tünews detail header and show the corresponding logos instead (with an link to the external news)
• Remove manual height for images in news content to fix whitespace on small screens
• Show last update for all events and left align it (native)

Side Effects

Not quite sure about the logos yet. The tünews logo still needs to be replaced, see https://chat.tuerantuer.org/digitalfabrik/pl/ey7w4kqw7jgiumdoxie8wikozr.

Checklist

• Followed the contributing guidelines and conventions
• Considered accessibility impacts and made the necessary adjustments
• Added or updated unit tests (if applicable)
• Added or updated documentation (if applicable)
• Added a release note for native (if applicable)

Testing

Test the whole new news feature with #4262.

Resolved Issues

Fixes: #2537

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[steffenkleinle]

Closed in favor of #4260