[Forwardport] fix: reset search mini-form when we have no data / an empty response

[dmytro-ch]

Original Pull Request

#18055

Description

Currently the search form does not reset the results when we have no result / data.

Fixed Issues (if relevant)

Manual testing scenarios

1. go to http://mag2opensource.basecom.de/catalogsearch/result/?q=pullover
2. write pullover in the search
3. autocomplete with result number appears
4. now append en so we have pulloveren
5. autocomplete still shows the results

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @dmytro-ch. Thank you for your contribution
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[rogyar]

@magento-engcom-team give me 2.3-develop instance

[magento-engcom-team]

Hi @rogyar. Thank you for your request. I'm working on Magento 2.3-develop instance for you

[magento-engcom-team]

Hi @rogyar, here is your Magento instance.
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[rogyar]

@magento-engcom-team give me test instance

[magento-engcom-team]

Hi @rogyar. Thank you for your request. I'm working on Magento instance for you

[magento-engcom-team]

Hi @rogyar, here is your new Magento instance.
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Login: admin Password: 123123q

[magento-engcom-team]

Hi @dmytro-ch. Thank you for your contribution.
We will aim to release these changes as part of 2.3.1.
Please check the release notes for final confirmation.