Antrea code coverage enhancement

[luolanzone]

Describe the problem/challenge you have Antrea is using codecov to analyze and generate overall test code coverage results. In the codecov site, we can see that Antrea's overall result go up and down with big differences. After a few investigation, we notice that Antrea uses codecov flags to categorize different tests and results. Some tests are only triggered when there are related changes, which means it's highly possible that it won't include all test results coverage in one PR or commit. This causes the data go up and down on the Antrea code coverage results.

Describe the solution you'd like We need to use consistent test coverage data and provide an coverage overview of Antrea project. After a few discussion, below are a few items which may help us to improve the code coverage.

• [x] Configuring Carryforward Flags to codecov setting to use a reference of past coverage for tests that are not run on the current commit.
• [x] Upload Multi-cluster e2e test coverage to codecov
• [ ] Create a jenkins job to trigger a fully test on main branch daily (not necessary after Carryforward is setting to true)
• [ ] Show overall test result in one place by getting coverage data via Codecov API(Suppose we can't reuse codecov site to show a clear coverage overview)
• [x] Add more test cases for difference packages. Tracked by issue #4142
• [ ] Add codecov badge/info to a file like coverage.md? you can refer to this repo

Anything else you would like to add?

[github-actions[bot]]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment, or this will be closed in 90 days

[github-actions[bot]]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment, or this will be closed in 90 days