Add specs for different contexts in which internal events custom matchers can be used

Problem

If we want to make internal event composable matchers the recommended approach for testing internal events/metrics, then it's very important that users don't bump up against weird edge cases or confusing expectations.

Desired Outcome

Common usage scenarios and contexts for the composable matchers are covered by tests.

Potential Solution

Add more tests covering scenarios like:

• with retries
• from controllers, services, migrations, workers, etc
• with & without cache clearing
• from feature tests

If any of the new test cases reveal bad behavior in the custom matchers, we should open follow-up issues for anything other than very minor changes.

How to verify

Further actions needed