[LL FIR] rename testdata to testData to avoid copyright generation

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/classId/enum.kt

@@ -0,0 +1,10 @@
+package one
+
+/* ClassId: one/MyEnum */enum class MyEnum {
+    ;
+
+    /* ClassId: one/MyEnum.InsideEnum */class InsideEnum
+    /* ClassId: one/MyEnum.ObjectInsideEnum */object ObjectInsideEnum {
+        /* ClassId: one/MyEnum.ObjectInsideEnum.Nested */typealias Nested
+    }
+}