KT-61032 [FIR] Add testData for invoke on K*Function* local variables

N.B. Method references currently also implicitly have such type

compiler/fir/analysis-tests/testData/resolve/extendedCheckers/unused/invokeKFunction.kt

@@ -0,0 +1,8 @@
+// WITH_STDLIB
+import kotlin.reflect.KFunction1
+
+fun foo(action: KFunction1<String, Int>): Int {
+    val <!UNUSED_VARIABLE!>localAction<!> = action
+
+    return localAction("hello")
+}