Fixed occasional insertions of fq-names by completion and similar effects

#KT-6182 Fixed
 #KT-6111 Fixed

idea/testData/completion/handlers/basic/ExtensionReceiverTypeArg.kt

@@ -0,0 +1,4 @@
+fun List<S<caret>>foo() {}
+
+// ELEMENT: String
+// TAIL_TEXT: "(kotlin)"

idea/testData/completion/handlers/basic/ExtensionReceiverTypeArg.kt.after

@@ -0,0 +1,4 @@
+fun List<String<caret>>foo() {}
+
+// ELEMENT: String
+// TAIL_TEXT: "(kotlin)"

idea/testData/completion/handlers/basic/SecondTypeArg.kt

@@ -0,0 +1,8 @@
+import java.util.HashMap
+
+fun foo() {
+    val v = HashMap<String, <caret>
+}
+
+// INVOCATION_COUNT: 2
+// ELEMENT: HashSet

idea/testData/completion/handlers/basic/SecondTypeArg.kt.after

@@ -0,0 +1,9 @@
+import java.util.HashMap
+import java.util.HashSet
+
+fun foo() {
+    val v = HashMap<String, HashSet<caret>
+}
+
+// INVOCATION_COUNT: 2
+// ELEMENT: HashSet

idea/testData/completion/handlers/basic/SuperTypeArg.kt

@@ -0,0 +1,8 @@
+class C : java.io.BufferedReader() {
+    override fun hashCode(): Int {
+        super<Buf<caret>
+    }
+}
+
+// INVOCATION_COUNT: 2
+// ELEMENT: BufferedReader

idea/testData/completion/handlers/basic/SuperTypeArg.kt.after

@@ -0,0 +1,10 @@
+import java.io.BufferedReader
+
+class C : java.io.BufferedReader() {
+    override fun hashCode(): Int {
+        super<BufferedReader<caret>
+    }
+}
+
+// INVOCATION_COUNT: 2
+// ELEMENT: BufferedReader