API Gateway dependency test

[strekm]

Description

Implement API Gateway module integration test that is using latest Kyma Istio module as dependency. Test should be executed on main (atm mod-dev), PRs, release and on Kyma Istio module release.
Kyma cli should be used to install certificates and ory components. Kyma Istio operator should installed using provided manifest.

• int test triggered on latest kyma istio release
• executed on main, PR, release
  - [] executed when new version of Kyma Istio operator is released we did decide against this because it requires kyma-project orgranization GH token with limited validity which will require rotation
• run dependency tests nightly if new Istio was released in the last 24 hours
• check main after merge

Reasons

Early tests of Istio releases

DoD:
- [ ] provide documentation
- [ ] release notes and What's New updates for Kyma customers
- [ ] provide unit tests

• provide integration tests
• test on production-like environment
  - [ ] verify resource limits
  - [ ] followup issue%
  - [ ] create release and bump in kyma
  - [ ] PR reviewer will verify code coverage and evaluate if it is acceptable

PRs

• API Gateway Istio dependency integration tests #543

[strekm]

#529