tests: test ordering of concurrent query in async mode

[Anton-2]

What is the motivation?

Following #164 and discussion with @maxwellflitton , extend async tests to catch concurrent response ordering error

Type of Change

• 📚 Examples / docs / tutorials / dependencies update
• 🔧 Bug fix (non-breaking change which fixes an issue)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix

What does this change do?

Add a test showing that current lock mechanism fails with concurrent queries taking different time to finish.

What is your testing strategy?

It's a test ;-)

Is this related to any issues?

#164 and async mode of this library in general

Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines