Allow to change start up options, like Kubernetes API before test start

```

cl, err := cluster.NewCluster(t, ...Option) 
```
Options could be
- cluster.K3sVersion1_28
- noSAWait (=>`waitForDefaultSACreation()`), 
- logLevel,
- etc

This would allow to find errors of components that are incompatible with different kubernetes API versions.