Slow test filter and highlighting in explorer UI

[DerYeger]

Clear and concise description of the problem

While it's already possible to sort tests by duration, this is based on the whole test file and not individual tests. As a result, it's not possible to quickly navigate to and analyze files that exceed the slowTestThreshold.

Suggested solution

Add a new filter for slow tests. This filter should operate on a test-level. Additionally, the duration of slow tests could use the yellow text color in the explorer UI.

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.