Copy: Support top-level declarations

idea/testData/refactoring/copy/copyTopLevelFunction/after/bar/a.kt

@@ -0,0 +1,8 @@
+package bar
+
+import foo.B
+
+fun a() {
+    a()
+    val b: B = B()
+}

idea/testData/refactoring/copy/copyTopLevelFunction/after/foo/test.kt

@@ -0,0 +1,11 @@
+package foo
+
+fun a() {
+    a()
+    val b: B = B()
+}
+
+class B {
+    val a: A = A()
+    val b: B = B()
+}

idea/testData/refactoring/copy/copyTopLevelFunction/before/foo/test.kt

@@ -0,0 +1,11 @@
+package foo
+
+fun <caret>a() {
+    a()
+    val b: B = B()
+}
+
+class B {
+    val a: A = A()
+    val b: B = B()
+}

idea/testData/refactoring/copy/copyTopLevelFunction/copyTopLevelFunction.test

@@ -0,0 +1,4 @@
+{
+  "mainFile": "foo/test.kt",
+  "targetPackage": "bar"
+}