fix(instances): domain edits start from the persistent definition

Edits that redefine a domain read the wrong XML:
- boot menu/order, vCPU hotplug and QoS read XMLDesc(0), which has no
  secrets, so every such edit, even on a stopped VM, removed the VNC
  password from the definition;
- console, video, CPU, memory and title/description edits read the live
  XML, so on a running VM pending changes (e.g. a new memory size) were
  reverted and runtime state was written into the definition.

All of them now read VIR_DOMAIN_XML_INACTIVE | SECURE (PERSISTENT_XML).
The console setters take the first graphics device of that definition
instead of looking it up by the live type.

Disk resize no longer redefines the domain. A running VM's image files
grow through blockResize, since qemu-img cannot take the lock QEMU
holds; block volumes (e.g. LVM) are grown by the storage pool first and
QEMU is then told the new size.

Live tests reproduce the losses on a RHEL qemu-kvm host; unit tests
check the XML flags, the console setters and the resize paths in CI.

vrtManager/test_console_setters.py

@@ -0,0 +1,44 @@
+import unittest
+from unittest.mock import MagicMock
+
+from django.conf import settings
+
+if not settings.configured:
+    settings.configure(MAC_OUI="52:54:10")
+
+from lxml import etree
+from vrtManager.instance import PERSISTENT_XML, wvmInstance
+
+LIVE = "<domain><devices><graphics type='vnc' passwd='live'><listen type='address'/></graphics></devices></domain>"
+PERSISTENT = "<domain><devices><graphics type='spice' passwd='old'><listen type='address'/></graphics></devices></domain>"
+
+
+def running_vm_with_pending_graphics_type():
+    vm = wvmInstance.__new__(wvmInstance)
+    vm.wvm = MagicMock()
+    vm._XMLDesc = MagicMock(side_effect=lambda flags: PERSISTENT if flags == PERSISTENT_XML else LIVE)
+    return vm
+
+
+class ConsoleSettersTestCase(unittest.TestCase):
+    """The graphics device to edit comes from the persistent definition."""
+
+    def defined_graphics(self, vm):
+        return etree.fromstring(vm.wvm.defineXML.call_args[0][0]).find("devices/graphics")
+
+    def test_setters_edit_the_persistent_graphics_device(self):
+        edits = {
+            "set_console_passwd": (lambda vm: vm.set_console_passwd("new"), "passwd", "new"),
+            "set_console_keymap": (lambda vm: vm.set_console_keymap("de"), "keymap", "de"),
+            "set_console_listener_addr": (lambda vm: vm.set_console_listener_addr("127.0.0.1"), "listen", "127.0.0.1"),
+            "set_console_type": (lambda vm: vm.set_console_type("vnc"), "type", "vnc"),
+        }
+        for name, (edit, attr, value) in edits.items():
+            with self.subTest(name):
+                vm = running_vm_with_pending_graphics_type()
+                edit(vm)
+                self.assertEqual(self.defined_graphics(vm).get(attr), value)
+
+
+if __name__ == "__main__":
+    unittest.main()