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

idea/testData/checker/regression/Jet124.kt

@@ -3,6 +3,6 @@ fun foo1() :  (Int) -> Int = { x: Int -> x }
 fun foo() {
   val h :  (Int) -> Int = foo1();
   h(1)
-  val m :  (Int) -> Int = {<warning descr="[UNUSED_PARAMETER] Parameter 'a' is never used">a</warning> : Int -> 1}//foo1()
+  val m :  (Int) -> Int = {a : Int -> 1}//foo1()
   m(1)
 }