Testplan for #10281 - service health and readiness checks

[dragonchaser]

We need to test the /healthz and /readyz of every service mentioned in #10281 for functionality (e2e). Therefore we need additional tests in our PHP-Suite.

IMHO there is no need to test them in k8s or k3s. It should be sufficient to check the output of the two endpoints with their conditions being met or unmet.

refs #8783

Tests:

• check for /healthz and /readyz for every services: [test-only] add test for checking service ready and health #10351
• during test stop the nats server and start again, check for /healthz and /readyz
  • issue: healthcheck not failing even when service registration is not successful #8783

Known bugs:

• Readiness check for some services returns 500 status code #10661
  Note: After this bug has been fixed, merge scenarios separated in this PR [full-ci][tests-only] Refactor service health and ready url in tests #10808

[ScharfViktor]

we have two ways(or more) how to check health of the service

service nats example:
curl http://127.0.0.1:9234/healthz - 200
and using CLI ocis/bin/ocis nats health - doesn't work (`ocis/bin/ocis nats version - also doesn't work)

in addition to checking the endpoinds we can check CLI using cliCommand suite. @dragonchaser should we fix cli health command for all services?

[PrajwolAmatya]

• during test stop the nats server and start again, check for /healthz and /readyz

Currently, there isn't any command to stop the nats server. Starting ocis with OCIS_EXCLUDE_RUN_SERVICES=nats and running nats separately with ocis/bin/ocis nats server doesn't seem feasible in CI. Trying to get pid for nats and kill pid will crash the ocis.

CC. @ScharfViktor

[PrajwolAmatya]

Need to wait for #10715 to be completed which will cover stopping and starting single ocis service. So, moving this to blocked for now.