add ChapterCount to manga object in categoryMangas endpoint (#349)

* adds ChapterCount to the Manga returned when accessing the array of Manga is a category

* removed a conflicting expresssion

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/CategoryManga.kt

@@ -70,12 +70,19 @@ object CategoryManga {
                 .slice(ChapterTable.id.count())
                 .select { (MangaTable.id eq ChapterTable.manga) and (ChapterTable.isDownloaded eq true) }
         )
+        val chapterCountExpression = wrapAsExpression<Long>(
+            ChapterTable
+                .slice(ChapterTable.id.count())
+                .select { (MangaTable.id eq ChapterTable.manga) }
+        )
 
-        val selectedColumns = MangaTable.columns + unreadExpression + downloadExpression
+        val selectedColumns = MangaTable.columns + unreadExpression + downloadExpression + chapterCountExpression
+        
         val transform: (ResultRow) -> MangaDataClass = {
             val dataClass = MangaTable.toDataClass(it)
             dataClass.unreadCount = it[unreadExpression]?.toInt()
             dataClass.downloadCount = it[downloadExpression]?.toInt()
+            dataClass.chapterCount = it[chapterCountExpression]?.toInt()
             dataClass
         }
 

server/src/main/kotlin/suwayomi/tachidesk/manga/model/dataclass/MangaDataClass.kt

@@ -36,7 +36,8 @@ data class MangaDataClass(
 
     val freshData: Boolean = false,
     var unreadCount: Int? = null,
-    var downloadCount: Int? = null
+    var downloadCount: Int? = null,
+    var chapterCount: Int? = null
 )
 
 data class PagedMangaListDataClass(