Move cloud metadata packages and kubernetes resources marshaling to internal

Decouples cloud provider metadata packages from kubernetes related code

Signed-off-by: Malte Poll <mp@edgeless.systems>

internal/cloud/azure/virtualnetwork.go

@@ -0,0 +1,25 @@
+package azure
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/network/armnetwork"
+)
+
+// getVirtualNetwork return the first virtual network found in the resource group.
+func (m *Metadata) getVirtualNetwork(ctx context.Context, resourceGroup string) (*armnetwork.VirtualNetwork, error) {
+	pager := m.virtualNetworksAPI.NewListPager(resourceGroup, nil)
+	for pager.More() {
+		page, err := pager.NextPage(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("retrieving virtual networks: %w", err)
+		}
+		for _, network := range page.Value {
+			if network != nil {
+				return network, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("no virtual network found in resource group %s", resourceGroup)
+}