Add tests for large context group config. [AI-assisted]

large.context.group.enabled = true for kustvakt.conf
large.context.group.enabled = false for kustvakt-dnb.conf

Large context group is generated during initialization and can be
disabled through KustvaktConfiguration. For the DNB instance, the
initialization is omitted so, the group should not be generated. In the
shared test database, the group exists though.

Change-Id: I8b7f76830918b5adb0442b869729cffe2dbce01b
diff --git a/Changes b/Changes
index 7d7df63..48eda79 100644
--- a/Changes
+++ b/Changes
@@ -4,6 +4,7 @@
 - Apply new kwic and shrinking properties for kustvakt-dnb
 - Fix handling non-existent large context group
 - Make large context group optional and disabled by default [AI-assisted]
+- Add tests for large context group config [AI-assisted]
 
 # version 1.2-SNAPSHOT