KT-5153 Smart completion should include objects from type

#KT-5153 Fixed

idea/testData/completion/handlers/smart/ObjectFromType.kt

@@ -0,0 +1,13 @@
+package p
+
+class Outer {
+    trait T {
+        object Null : T { }
+    }
+}
+
+fun foo(): Outer.T {
+    return <caret>
+}
+
+// ELEMENT: "T.Null"

idea/testData/completion/handlers/smart/ObjectFromType.kt.after

@@ -0,0 +1,13 @@
+package p
+
+class Outer {
+    trait T {
+        object Null : T { }
+    }
+}
+
+fun foo(): Outer.T {
+    return Outer.T.Null<caret>
+}
+
+// ELEMENT: "T.Null"

idea/testData/completion/smart/ObjectsFromType.kt

@@ -0,0 +1,14 @@
+package p
+
+trait T {
+    object Null : T { }
+
+    object Other {}
+}
+
+fun foo(): T {
+    return <caret>
+}
+
+// EXIST: { lookupString:"T.Null", itemText:"T.Null", tailText:" (p)", typeText:"T" }
+// ABSENT: T.Other