[chore] Unit tests: Expand expect with testing-library helpers

[ThieryMichel]

Problem

Could not use matcher like expect(...).toBeDisabled in test.

Solution

initialize (import) @testing-library/jest-dom in jest test setup.

How To Test

Try to use testing library expect method, like toBeDisabled or toHaveAttribute.

Additional Checks

• The PR targets master for a bugfix, or next for a feature
• The PR includes unit tests (if not possible, describe why)
• The PR includes one or several stories (if not possible, describe why)
• The documentation is up to date

Also, please make sure to read the contributing guidelines.

[slax57]

Sweet!