Introduce UNUSED_ANONYMOUS_PARAMETER for anonymous functions

It is not reported for 1.0 language version because
renaming to _ is not possible. It has weak warning severity

So #KT-8813 Fixed
So #KT-16875 Fixed

compiler/testData/diagnostics/testsWithStdLib/regression/ea70485_functionTypeInheritor.kt

@@ -4,7 +4,7 @@ class O : Function2<Int, String, Unit> {
 }
 
 fun test() {
-    val a = fun(<!UNUSED_PARAMETER!>o<!>: O) {
+    val a = fun(<!UNUSED_ANONYMOUS_PARAMETER!>o<!>: O) {
     }
     a <!TYPE_MISMATCH!>{}<!>
 }