Add support for test coverage reports via pytest-cov.

[dfitchett]

What was the problem?

EE projects did not include test coverage.

Associated tickets or Slack threads:

• Add test coverage reports to EE projects in VRO. #2988

How does this fix it?[^1]

Adds pytest-cov to domain-ee subprojects.

How to test this PR

• Run via gradle: ./gradlew :domain-ee:test
• Run via pytest from individual project folder

[github-actions]

Test Results

109 tests  ±0   109 ✅ ±0   35s ⏱️ -1s
 33 suites ±0     0 💤 ±0 
 33 files   ±0     0 ❌ ±0 

Results for commit 6e0d6ac. ± Comparison against base commit 9e49b41.

[github-actions]

JaCoCo Test Coverage

Overall Project	64.3%	❌

There is no coverage information present for the Files changed

[nanotone]

Approving, with the understanding that this change doesn't incorporate test coverage reports into GitHub PR feedback.

[dfitchett]

Approving, with the understanding that this change doesn't incorporate test coverage reports into GitHub PR feedback.

Seemed like more work than it was worth. If there isn't 80% pytest coverage, then the code check will fail.