Add functionality to specify "YAKS_TEST_ID"

Hi all!

This is a follow up on the issue 268 https://github.com/citrusframework/yaks/issues/268.

I added two checks at the beginning of the test to determine, if the istio proxy is ready. Here is the code:

Given Kubernetes resource polling configuration
| maxAttempts | 10 |
| delayBetweenAttempts | 1000 |
Given Kubernetes pod ${YAKS_TEST_NAME}${YAKS_TEST_ID} should print Envoy proxy is ready

Given URL: http://localhost:15021
Then wait for path /healthz/ready

Unfortunately I still get the error, that the maven dependencies for the presto-driver could not be resolved. So this exception gets triggered before even one of the steps gets executed.

To check whether the istio proxy is ready I probably have to move that check into a pre script. Here it would be helpful to define the environment variable "YAKS_TEST_ID" so I can use the name of the test-pod in the pre script. Starting the test with "yaks test -e YAKS_TEST_ID=$RANDOM_ID file.feature" only added an additional environmental variable to the test pod and did not change the name of it.

Start by reviewing issue 268 and the yaks test command behavior described here, including how the test pod name and environment variables are assembled. Trace how pre scripts receive YAKS_TEST_NAME and YAKS_TEST_ID, then verify that specifying YAKS_TEST_ID changes the pod name as intended without treating it only as an extra pod environment variable.

Written by the indexing model from the issue text.