test: Add two FAILING unit-tests for UnMarshallLimitNamespace (#167)

The two failing test cases include:
- when namespace has no gateway name then return an error
- when namespace has no domain name then return an error

In these test-cases we leave the separator (either "/" or "#"), which causes the function to return an error when the gateway name or domain name is missing. In the last two test cases:
- when namespace only has gateway name (missing 'namespace/') and domain then return an error
- when namespace only has namespace name (missing '/gwName') and domain then return an error
the separator (/) is missing along with the namespace or gateway names, causing the function to return the correct error message.

pkg/common/common_test.go

@@ -243,14 +243,28 @@ func TestUnMarshallLimitNamespace(t *testing.T) {
 			expectedError:  true,
 		},
 		{
-			name:           "when namespace only has gateway name (missing 'namespace/') then return an error",
+			name:           "when namespace has no gateway name then return an error",
+			namespace:      "exampleNS/#domain.com",
+			expectedKey:    client.ObjectKey{},
+			expectedDomain: "",
+			expectedError:  true,
+		},
+		{
+			name:           "when namespace has no domain name then return an error",
+			namespace:      "exampleNS/exampleGW#",
+			expectedKey:    client.ObjectKey{},
+			expectedDomain: "",
+			expectedError:  true,
+		},
+		{
+			name:           "when namespace only has gateway name (missing 'namespace/') and domain then return an error",
 			namespace:      "exampleGW#domain.com",
 			expectedKey:    client.ObjectKey{},
 			expectedDomain: "",
 			expectedError:  true,
 		},
 		{
-			name:           "when namespace only has namespace name (missing '/gwName') then return an error",
+			name:           "when namespace only has namespace name (missing '/gwName') and domain then return an error",
 			namespace:      "exampleNS#domain.com",
 			expectedKey:    client.ObjectKey{},
 			expectedDomain: "",