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

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/getOrBuildFir/wholeDeclaration/functionValueParameter.txt

@@ -0,0 +1,11 @@
+KT element: KtParameter
+FIR element: FirValueParameterImpl
+FIR source kind: KtRealSourceElementKind
+
+FIR element rendered:
+[ResolvedTo(BODY_RESOLVE)] x: R|kotlin/Int|
+
+FIR FILE:
+FILE: [ResolvedTo(IMPORTS)] functionValueParameter.kt
+    public final [ResolvedTo(BODY_RESOLVE)] fun foo([ResolvedTo(BODY_RESOLVE)] x: R|kotlin/Int|): R|kotlin/Unit| {
+    }