Expose exec Standard error

[IvanJosipovic]

Describe the bug
When connecting to a new Azure AKS instance, kubelogin exposes a URL that we must open. I think we have to somehow expose this in the client so the user can interact with the URL as needed. Kubelogin exposes this output as Standard Error.

Kubernetes C# SDK Client Version
10.1.19

Server Kubernetes Version
1.25.4

Dotnet Runtime Version
net6

To Reproduce
Steps to reproduce the behavior:
Install Azure CLI

az aks get-credentials --resource-group $ResourceGroup --name $Name --subscription $Subscription

Load Kubeconfig with the client and attempt to list Pods etc.

Expected behavior
Client should expose standard error for exec and keep the process open and allow us view the output.

Where do you run your app with Kubernetes SDK (please complete the following information):

• OS: Windows
• Cloud: Azure

[IvanJosipovic]

It appears that there is code in this library that should handle this scenario. However, it appears that its hanging on

csharp/src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

Lines 560 to 561 in 6ce40c1

	var stdout = process.StandardOutput.ReadToEnd();
	var stderr = process.StandardError.ReadToEnd();

See PR fix here, #1267

Its also worth noting that due to the blocking above, the following line doesn't appear work. This is actually a good thing as the user needs time to go through the auth flow that is required by AKS.

csharp/src/KubernetesClient/KubernetesClientConfiguration.ConfigFile.cs

Lines 567 to 568 in 6ce40c1

	// Wait for a maximum of 5 seconds, if a response takes longer probably something went wrong...
	process.WaitForExit(5);