Create From Usage: Fix rendering of nullable types

idea/testData/quickfix/createFromUsage/createVariable/parameter/afterNullableType.kt

@@ -0,0 +1,6 @@
+// "Create parameter 'foo'" "true"
+
+fun test(n: Int,
+         foo: Int?) {
+    val t: Int? = foo
+}

idea/testData/quickfix/createFromUsage/createVariable/parameter/beforeNullableType.kt

@@ -0,0 +1,5 @@
+// "Create parameter 'foo'" "true"
+
+fun test(n: Int) {
+    val t: Int? = <caret>foo
+}