KT-1633 support completion of named function parameters

idea/testData/completion/basic/common/namedParameters/NamedParamsInConstructor.kt

@@ -0,0 +1,10 @@
+package test
+
+class Foo(pFirst: String? = null, val pSecond: Int = 1) { }
+
+fun other() {
+    Foo(p<caret>)
+}
+
+// EXIST: {"lookupString":"pFirst","tailText":"String?","itemText":"pFirst = "}
+// EXIST: {"lookupString":"pSecond","tailText":"Int","itemText":"pSecond = "}