Java: Implemented completion assistance for Var/Method Handle - suggest field/method name, autocomplete the signature (IDEA-167319)

java/java-tests/testData/codeInsight/completion/invokeHandle/VirtualPrefixed.java

@@ -0,0 +1,8 @@
+import java.lang.invoke.*;
+
+public class Main {
+  void foo() throws Throwable {
+    MethodHandles.Lookup lookup = MethodHandles.lookup();
+    lookup.findVirtual(Test.class, "m<caret>");
+  }
+}