[144][test] Fix a memory leak regarding tests failures

During an execution of a suite, if some fail during the failureTearDown
method execution, all the data used by these tests leak until the end of
the suite execution.
This can be problematic in case of long suite with several failures and
lot of data. It increases the risk of OutOfMemory error.

Bug: #144

plugins/org.eclipse.sirius.tests.swtbot.support/src/org/eclipse/sirius/tests/swtbot/support/api/AbstractSiriusSwtBotGefTestCase.java

@@ -1708,6 +1708,9 @@ public void run() {
             setErrorCatchActive(false);
             setWarningCatchActive(false);
 
+            // All tearDown tasks have been done, now all fields can be safely clear (before below final checks).
+            new TestCaseCleaner(this).clearAllFields();
+
             crossRefDetector.assertNoCrossReferenceAdapterFound();
             checkLogs();
         }
@@ -1924,8 +1927,6 @@ protected Color getFigureBackgroundColor(IFigure parentFigure, Class<? extends F
     protected void tearDown() throws Exception {
         failureTearDown();
 
-        new TestCaseCleaner(this).clearAllFields();
-
         super.tearDown();
         setErrorCatchActive(false);
         setWarningCatchActive(false);