GF-60665: Close ExpandableInput when pressing Enter.

Issue
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The `ExpandableInput` does not close when pressing `enter` in the input field.

Fix
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We handle the `keydown` event of the `Input` control and call `expandContract` if we detect that the `enter` key was pressed. Additionally, to allow re-spotting of the header upon close, we manually call `setPointerMode(false)` and unfreeze `Spotlight`. Lastly, we remove the `onSpotlightSelect` handler as the event is being captured by `InputDecorator` and the handler is never being run.

This PR also addresses ANG-576.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>