feat(instances): a shut-off VM with a TPM migrates with its TPM state

A shut-off VM with TPM state, as every Windows 11 VM, was refused for
migration: the state is a file of the source host, and an offline move
would start it there with a new TPM. Such a VM now migrates as a shut-off
VM with disks to copy does: its UEFI variables are copied, it is started
paused, its CPUs never run, migrates live, which carries the TPM state,
and is shut off on the destination. A shut-off VM with a saved state is
refused before any of that, for every way it moves: started paused, it
would resume and then lose the saved memory.

The clone tab says that a clone gets a new, empty TPM, and the destroy
page that the TPM state goes with the VM.

instances/tests/test_destroy.py

@@ -175,6 +175,14 @@ class DestroyOrderTestCase(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(calls, [])
 
+    def test_the_confirmation_page_says_the_tpm_state_goes(self):
+        for tpm, shown in (("emulator", True), (None, False), ("custom", False)):
+            with self.subTest(tpm=tpm), patch("instances.models.wvmInstance") as wvm:
+                wvm.return_value.get_status.return_value = 5
+                wvm.return_value.get_tpm.return_value = tpm
+                response = self.client.get(reverse("instances:destroy", args=[self.instance.id]))
+                self.assertEqual(b"Its TPM state is deleted" in response.content, shown)
+
     def test_the_confirmation_page_of_a_paused_vm_offers_the_form(self):
         with patch("instances.models.wvmInstance") as wvm:
             wvm.return_value.get_status.return_value = 3  # paused