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

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/lazyResolve/errors/anonymousObjectInInvalidPosition.kt

@@ -0,0 +1,7 @@
+private val resolve<caret>Me: A = null = <expr>object : A<Int> {
+    override fun x() {}
+}</expr>
+
+interface A<T> {
+    fun x()
+}