Field can be local: added support for nested and local classes (IDEA-206647)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/convert2Local/afterLocalClass.java

@@ -0,0 +1,12 @@
+// "Convert field to local variable in method 'test'" "true"
+class Foo {
+  void test() {
+    class Bar {
+
+        void test() {
+            int x = 2; // could be local
+            System.out.println(x);
+      }
+    }
+  }
+}