Add test coverage support through CodeCov

[caponetto]

What changes were proposed in this pull request?

CodeCov is a useful tool that provides a dashboard showing the coverage for the branches and comments on every PR regarding how the new code stands with test coverage. It will consider tests from Pytest, Jest, and Cypress.

Cherry-picked from ODH Elyra

How was this pull request tested?

Through CI runs and manual tests

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[codecov-commenter]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

Thanks for integrating Codecov - We've got you covered ☂️