Add less important disp template and disp

The default-dvm is the global and local default_dispvm, this means that
trying to remove the qube requires changing a lot of references.

Fixes: QubesOS/qubes-issues#10227
For: QubesOS/qubes-issues#1512

Author: ben-grande

qubesadmin/tests/mock_app.py

@@ -1011,6 +1011,22 @@ def __init__(self):
             template="default-dvm",
         )
 
+        self._qubes["test-alt-dvm"] = MockQube(
+            name="test-alt-dvm",
+            qapp=self,
+            klass="AppVM",
+            template_for_dispvms="True",
+            template="fedora-36",
+            features={"appmenus-dispvm": "1"},
+        )
+
+        self._qubes["test-alt-disp"] = MockQube(
+            name="test-alt-disp",
+            qapp=self,
+            klass="DispVM",
+            template="test-alt-dvm",
+        )
+
         self._qubes["test-vm"] = MockQube(
             name="test-vm",
             qapp=self,