Fix network sorting in API tests

There is a mismatch in some tests because sorted() sorts in ASCII
order - digits are followed by uppercase characters and then
lowercase characters. That doesn't work if a network's name starts
with a capital letter.

Closes-Bug: #2049211
Change-Id: I8328d7d8ca7b49b99feb24d77525abdc064aae80
diff --git a/neutron_tempest_plugin/api/base.py b/neutron_tempest_plugin/api/base.py
index e3c9aad..28d556a 100644
--- a/neutron_tempest_plugin/api/base.py
+++ b/neutron_tempest_plugin/api/base.py
@@ -1437,7 +1437,9 @@
         self.assertNotEmpty(
             resources, "%s list returned is empty" % self.resource)
         retrieved_names = [res[self.field] for res in resources]
-        expected = sorted(retrieved_names)
+        # sort without taking into account whether the network is named with
+        # a capital letter or not
+        expected = sorted(retrieved_names, key=lambda v: v.upper())
         if direction == constants.SORT_DIRECTION_DESC:
             expected = list(reversed(expected))
         self.assertEqual(expected, retrieved_names)