Integrate ibmcloud cli into kubectl to obtain access & refresh token if they expired

So far, the workflow is as follows:

1. login / authentication with the ibmcloud CLI

2. obtaining the kubeconfig with the ibmcloud CLI

3. using the current kubeconfig with integrated authentication data

4. if this data expires, start from 1.

Other cloud platforms, such as Google, integrate their CLI directly into the kubeconfig and use it there to obtain the authentication data to access the Kubernetes API. Especially in automated processes that work with kubeconfig, the current process poses a problem.