Copy: Copy entire file if it contains just a selected declaration

idea/testData/refactoring/copy/copySingleClassWithRename/after/bar/B.kt

@@ -0,0 +1,7 @@
+package bar
+
+// test
+
+class B
+
+// test2

idea/testData/refactoring/copy/copySingleClassWithRename/after/foo/A.kt

@@ -0,0 +1,7 @@
+package foo
+
+// test
+
+class A
+
+// test2

idea/testData/refactoring/copy/copySingleClassWithRename/before/foo/A.kt

@@ -0,0 +1,7 @@
+package foo
+
+// test
+
+class <caret>A
+
+// test2

idea/testData/refactoring/copy/copySingleClassWithRename/copySingleClassWithRename.test

@@ -0,0 +1,5 @@
+{
+  "mainFile": "foo/A.kt",
+  "targetPackage": "bar",
+  "newName": "B"
+}