Fix certification failure for Commercetools Connect

[leungkinghin-ct]

• Move c8 to devDependencies in package.json as it uses vulnerable dependencies
• Exclude integration test and e2e test from npm run test command for Commercetools Connect, and execute npm run test-ci in Github Action
• Use mock config in notification module unit test
• Update documentation

[praveenkumarct]

You don't need to run Integration and e2e tests completely in the main branch?

I think still there are other users using this repo.
May you could consider ignoring only those tests which are failing at the moment. We can fix them later(Try to create a issue for our reference).

[praveenkumarct]

You don't need to run Integration and e2e tests completely in the main branch?

I think still there are other users using this repo. May you could consider ignoring only those tests which are failing at the moment. We can fix them later(Try to create a issue for our reference).

I misunderstood the changes, Yes the code looks good for me.

[leungkinghin-ct]

You don't need to run Integration and e2e tests completely in the main branch?

I think still there are other users using this repo. May you could consider ignoring only those tests which are failing at the moment. We can fix them later(Try to create a issue for our reference).

The change in this PR would not affect the integration test and e2e test in CI/CD. Since Commercetools Connect does not get the adyen config from env-var during build, that's why we split those existing npm commands (npm run test is now dedicated for Commercetools Connect and execute unit test only).