[SLC] SymbolLightClassForEnumEntry: improve implementation

^KT-54051
^KT-50241

compiler/testData/asJava/lightClasses/EnumEntry.kt

@@ -0,0 +1,28 @@
+// p.KotlinEnum.FirstEntry
+
+package p
+
+enum class KotlinEnum {
+    FirstEntry {
+        fun firstEntryFun() = Unit
+        val firstEntryProp = 4
+        var variable: Int = 1
+            get() = 2
+            private set
+
+        override fun abstractFun() {
+            TODO("Not yet implemented")
+        }
+    },
+
+    SecondEntry {
+        fun secondEntryFun() = 3
+        val secondEntryProp = 2
+
+        override fun abstractFun() {
+            TODO("Not yet implemented")
+        }
+    };
+
+    abstract fun abstractFun()
+}