KT-5959 Imports should be inserted on paste from java with conversion to Kotlin

#KT-5959 Fixed

idea/testData/copyPaste/conversion/AddImportsButNoConversion2.java

@@ -0,0 +1,9 @@
+// NO_CONVERSION_EXPECTED
+import java.io.*;
+import java.util.*;
+
+class C {
+    void foo(List<Character> list) {
+        <selection>list.add(File.separatorChar)</selection>
+    }
+}