[fixes #2838] Handle anonymous classes properly

Generated qualified names (e.g. Outer.Inner) now stop at anonymous
classes instead of adding an empty part. All handlers that add static
fields/methods/types now add error messages instead of generating
invalid code.

test/transform/resource/after-delombok/WithInAnonymousClass.java

@@ -0,0 +1,19 @@
+public class WithInAnonymousClass {
+	Object annonymous = new Object() {
+
+		class Inner {
+			private Inner(String string) {
+			}
+
+			private String string;
+
+			/**
+			 * @return a clone of this object, except with this updated property (returns {@code this} if an identical value is passed).
+			 */
+			@java.lang.SuppressWarnings("all")
+			public Inner withString(final String string) {
+				return this.string == string ? this : new Inner(string);
+			}
+		}
+	};
+}