Add Go wrappers for Get/SetVirtualDiskInformation win32 APIs

SetVirtualDiskInformation API is required for running confidential windows containers. The
VHDs used for starting confidential pods/UVMs need to have a specific disk
identifier. These newly added APIs will be used when preparing the VHDs for confidential
pods.

Signed-off-by: Amit <ambarve@microsoft.com>

vhd/vhd_test.go

@@ -0,0 +1,59 @@
+//go:build windows
+
+package vhd
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/Microsoft/go-winio/pkg/guid"
+)
+
+func TestVirtualDiskIdentifier(t *testing.T) {
+	// Create a temporary directory for the test
+	tempDir := t.TempDir()
+	// TODO(ambarve): We should add a test for VHD too, but our current create VHD API
+	// seem to only work for VHDX.
+	vhdPath := filepath.Join(tempDir, "test.vhdx")
+
+	// Create the virtual disk
+	if err := CreateVhdx(vhdPath, 1, 1); err != nil { // 1GB, 1MB block size
+		t.Fatalf("failed to create virtual disk: %s", err)
+	}
+	defer os.Remove(vhdPath)
+
+	// Get the initial identifier
+	initialID, err := GetVirtualDiskIdentifier(vhdPath)
+	if err != nil {
+		t.Fatalf("failed to get initial virtual disk identifier: %s", err)
+	}
+	t.Logf("initial identifier: %s", initialID.String())
+
+	// Create a new GUID to set
+	newID := guid.GUID{
+		Data1: 0x12345678,
+		Data2: 0x1234,
+		Data3: 0x5678,
+		Data4: [8]byte{0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0},
+	}
+	t.Logf("setting new identifier: %s", newID.String())
+
+	// Set the new identifier
+	if err := SetVirtualDiskIdentifier(vhdPath, newID); err != nil {
+		t.Fatalf("failed to set virtual disk identifier: %s", err)
+	}
+
+	// Get the identifier again to verify it was set correctly
+	retrievedID, err := GetVirtualDiskIdentifier(vhdPath)
+	if err != nil {
+		t.Fatalf("failed to get virtual disk identifier after setting: %s", err)
+	}
+	t.Logf("retrieved identifier: %s", retrievedID.String())
+
+	// Verify the retrieved ID matches the one we set
+	if retrievedID != newID {
+		t.Errorf("retrieved identifier does not match set identifier.\nExpected: %s\nGot: %s",
+			newID.String(), retrievedID.String())
+	}
+}