Unused symbol inspection should detect enum entry

#KT-30612 Fixed

idea/testData/quickfix/removeUnused/unusedEnumEntry.kt

@@ -0,0 +1,13 @@
+// "Safe delete 'WORLD'" "true"
+enum class MyEnum(val i: Int) {
+    HELLO(42),
+    WORLD<caret>("42"),
+    E(24)
+    ;
+
+    constructor(s: String): this(42)
+}
+
+fun test() {
+    MyEnum.HELLO
+}