Test coverage on CI

[subzero10]

I would like to get your feedback on the following:

• Should we introduce a minimum test coverage check on our CI for the js monorepo (though different per js package)?

Context:

• We have a decent amount of tests in most of our packages. We should make sure that we keep this consistency as we make changes.
• Separately, but similarly, for the packages that don't have tests at all, we can introduce a testing suite and aim to improve coverage gradually with these checks.