Introduce inspection for determining if a forEach parameter is unused

#KT-22068 Fixed

idea/testData/inspections/forEachParameterNotUsed/test.kt

@@ -0,0 +1,11 @@
+fun test() {
+    val items = listOf<Any>()
+    items.forEach { }
+    items.forEach { item -> }
+    items.forEach { doSomething(it) }
+    items.forEach { item -> doSomething(item) }
+    items.forEach { items.forEach { doSomething(it) } }
+    items.forEach { items.forEach { thing -> doSomething(it); doSomething(thing) } }
+}
+
+fun doSomething(item: Any) {}