Explore More Elegant Solution For Re-Focusing The First Input In Audience Selection Panel

## Feature Description

Currently when audience sync action is invoked on first panel opening, first input in the panel is not focused afterwards. There is also a preview block, shown before the inputs are loaded, although in my tests focus is lost after re-sync action happens.

Current implementation is in `assets/js/modules/analytics-4/components/audience-segmentation/dashboard/AudienceSelectionPanel/AudienceItems.js` after `TODO` comment

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## Acceptance criteria

* When opening the "Change groups" panel in Audience Selection panel, the selected checkbox (first one) should not lose focus after the available audiences are synced in the background.

## Implementation Brief

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### Test Coverage

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## QA Brief

*

## Changelog entry

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Read the implementation after the TODO in assets/js/modules/analytics-4/components/audience-segmentation/dashboard/AudienceSelectionPanel/AudienceItems.js. Reproduce opening the Change groups panel while audiences sync in the background, then inspect how the preview and inputs affect focus. Done means the selected first checkbox retains focus after syncing.

Written by the indexing model from the issue text.