Add support for Azure Workload Identity

[EppO]

Another take based on robusta-dev/robusta#975

[EppO]

To test it you need to follow this guide: https://learn.microsoft.com/en-us/azure/aks/workload-identity-deploy-cluster

In a nutshell:

1. Create a Managed Identity
2. Assign the appropriate permissions to the Managed Identity on the Azure Resource
3. Create a Service Account
4. Federate the Managed Identity with the Service Account
5. Add the Managed Identity's client ID to the Service Account's annotations and azure.workload.identity/use: "true" label to the Pod spec.

[pavangudiwada]

Hi @EppO, thanks for the PR, I'm working on testing this PR. Do you have a test file used to test this? Also can you please update the docs in the README about how to use this?

[CLAassistant]

All committers have signed the CLA.

[EppO]

Hi @pavangudiwada,

sorry for the late reply. I rebased the PR on top of the latest master, I added documentation how to use it and added some sensible default values when using Azure.
I may have introduced a breaking change with changing type of azure_use_managed_id from string to boolean but I did it from a consistency point of view. Let me know if you want me to roll back to string.