Refactor method/constructor calls in codegen

- use ResolvedCall where possible
- 'call' parameter to invokeMethodWithArguments was used only to generate
  callee, e.g. in "A()" where A is an expression which can be invoke()'d.
  In case of constructors and enum entry delegation specifiers there's no need
  to generate callee, so 'call' is made Nullable with a subsequent assert
- remove generateJavaConstructorCall() method, since it did no useful work.
  Java constructor invocation is broken anyway and needs to be fixed (KT-3532)
- minor code style / formatting issues fixed, several methods renamed to better
  reflect semantics

compiler/testData/codegen/boxWithJava/functions/constructor.java

@@ -0,0 +1,7 @@
+class A {
+    public A() {}
+
+    public A(String x) {}
+
+    public A(long l, double z) {}
+}