Move: Fix incorrect FqName when moving declaration to default package

#KT-15586 Fixed

idea/testData/multiFileIntentions/moveDeclarationToSeparateFile/moveClassToFileInDefaultPackage/after/a.kt

@@ -0,0 +1,6 @@
+class a {
+    companion object b {
+        fun c() = "..."
+    }
+    fun d() = c()
+}

idea/testData/multiFileIntentions/moveDeclarationToSeparateFile/moveClassToFileInDefaultPackage/after/test.kt

@@ -0,0 +1,3 @@
+fun foo() {
+
+}

idea/testData/multiFileIntentions/moveDeclarationToSeparateFile/moveClassToFileInDefaultPackage/before/test.kt

@@ -0,0 +1,10 @@
+class <caret>a {
+    companion object b {
+        fun c() = "..."
+    }
+    fun d() = c()
+}
+
+fun foo() {
+
+}

idea/testData/multiFileIntentions/moveDeclarationToSeparateFile/moveClassToFileInDefaultPackage/moveClassToFileInDefaultPackage.test

@@ -0,0 +1,4 @@
+{
+  "mainFile": "test.kt",
+  "intentionClass": "org.jetbrains.kotlin.idea.refactoring.move.moveDeclarations.MoveDeclarationToSeparateFileIntention"
+}