Integration test for swatches types in attribute configuration added

[rogyar]

Description

This PR adds an integration test for Magento\Swatches\Observer\AddSwatchAttributeTypeObserver which checks that the swatches types are added to the attribute configuration form.

Fixed Issues (if relevant)

N/A

Manual testing scenarios

N/A

[magento-engcom-team]

Hi @rogyar. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

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[magento-engcom-team]

Hi @sidolov, thank you for the review.
ENGCOM-2936 has been created to process this Pull Request

[magento-engcom-team]

Hi @rogyar. Thank you for your contribution.
We will aim to release these changes as part of 2.2.8.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.