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

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/fileStructure/enumClassScript.kts

@@ -0,0 +1,13 @@
+/* RootScriptStructureElement */enum class A {/* ClassDeclarationStructureElement */
+    X,/* DeclarationStructureElement */
+    Y,/* DeclarationStructureElement */
+    Z
+
+    ;/* DeclarationStructureElement */
+
+    fun foo(){/* DeclarationStructureElement */}
+
+    val x = 10/* DeclarationStructureElement */
+
+    fun bar() = 10/* DeclarationStructureElement */
+}