Smart completion: fix anonymous object code style (KT-29572)

#KT-29572 Fixed

idea/idea-completion/testData/smart/anonymousObject/1.kt

@@ -3,4 +3,4 @@ interface Foo
 var a : Foo = <caret>
 
 // ABSENT: Foo
-// EXIST: { lookupString:"object", itemText:"object: Foo{...}" }
+// EXIST: { lookupString:"object", itemText:"object : Foo{...}" }

idea/idea-completion/testData/smart/anonymousObject/2.kt

@@ -3,4 +3,4 @@ abstract class Foo
 var a : Foo = <caret>
 
 // ABSENT: Foo
-// EXIST: { lookupString:"object", itemText:"object: Foo(){...}" }
+// EXIST: { lookupString:"object", itemText:"object : Foo(){...}" }

idea/idea-completion/testData/smart/anonymousObject/ForJavaInterface.kt

@@ -1,4 +1,4 @@
 var a : Appendable = <caret>
 
 // ABSENT: Appendable
-// EXIST: { lookupString:"object", itemText:"object: Appendable{...}" }
+// EXIST: { lookupString:"object", itemText:"object : Appendable{...}" }

idea/idea-completion/testData/smart/anonymousObject/UninferredTypeArgs.kt

@@ -6,4 +6,4 @@ fun g() {
     foo(<caret>)
 }
 
-// EXIST: { lookupString:"object", itemText:"object: A<...>{...}" }
+// EXIST: { lookupString:"object", itemText:"object : A<...>{...}" }

idea/idea-completion/testData/smart/anonymousObject/WithPrefix.kt

@@ -2,4 +2,4 @@ interface Foo
 
 var a : Foo = o<caret>
 
-// EXIST: { lookupString:"object", itemText:"object: Foo{...}" }
+// EXIST: { lookupString:"object", itemText:"object : Foo{...}" }