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

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/fileStructure/localDeclarationsInAccessor.kt

@@ -0,0 +1,32 @@
+class Outer {/* ClassDeclarationStructureElement */
+    val i: Int = 1/* DeclarationStructureElement */
+        get() {
+            class Inner {
+                var i: Int = 2
+                    get() {
+                        field++
+                        return field
+                    }
+                val j: Int = 3
+                    get() {
+                        field = 42
+                        return field
+                    }
+
+                fun innerMember() {
+                    field++
+                }
+            }
+            return field
+        }
+
+    val j: Int = 4/* DeclarationStructureElement */
+        get() {
+            fun local() {
+                field++
+                field++
+            }
+            local()
+            return field
+        }
+}