az login support for Azure AD workload identity with Azure Kubernetes Service

**Related command**
az login

**Is your feature request related to a problem? Please describe.**
Currently if using workload identity and azure cli, az login must be specifically configured for login

**Describe the solution you'd like**
similar to az login --identity, maybe something like az login --workflow-identity
**Describe alternatives you've considered**
You can work around it currently using
az login --federated-token "$(cat $AZURE_FEDERATED_TOKEN_FILE)" --service-principal -u $AZURE_CLIENT_ID -t $AZURE_TENANT_ID

**Additional context**
For the client libraries a specific class is available `WorkloadIdentityCredential`

More generally it would be nice if az login had a way to use something similar to `DefaultAzureCredential` which would allow scripts to be more portable depending on execution context