Restore equals/hashCode in ChapterTransition (closes #2461)

app/src/main/java/eu/kanade/tachiyomi/ui/reader/model/ChapterTransition.kt

@@ -12,6 +12,20 @@ sealed class ChapterTransition {
             override val from: ReaderChapter, override val to: ReaderChapter?
     ) : ChapterTransition()
 
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is ChapterTransition) return false
+        if (from == other.from && to == other.to) return true
+        if (from == other.to && to == other.from) return true
+        return false
+    }
+
+    override fun hashCode(): Int {
+        var result = from.hashCode()
+        result = 31 * result + (to?.hashCode() ?: 0)
+        return result
+    }
+
     override fun toString(): String {
         return "${javaClass.simpleName}(from=${from.chapter.url}, to=${to?.chapter?.url})"
     }