feat(Layout): use advancedHeader layout for RSS

[adamweeks]

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
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• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

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What kind of change does this PR introduce?

The existing layout for the RSS header widget does not utilize the advancedHeader feature. It also is loading from an RSS feed that no longer exists. This PR fixes both of those issues.