junit: check for junit classes available in scope before proceeding with costly checks (SCL-16058)

GitOrigin-RevId: 34f3dda8a83aada3c78c9888aa995d010af2a62a

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/moveInitializerToSetUp/afterjUnit4.java

@@ -1,8 +1,10 @@
+import org.junit.Before;
+
 // "Move initializer to setUp method" "true"
 public class X {
   <caret>int i;
 
-    @org.junit.Before
+    @Before
     public void setUp() throws Exception {
         i = 7;
     }