Manga cover updates (#3101)

* cover caching overhaul

* add ui for removing custom cover

* skip some loading work

* minor cleanup

* allow refresh library metadata to refresh local manga

* rename metadata_date to cover_last_modified

* rearrange removeMangaFromLibrary

* change custom cover directory
add setting for updating cover when refreshing library

* remove toggle and explicit action for updating covers

app/src/main/java/eu/kanade/tachiyomi/ui/recent/history/HistoryHolder.kt

@@ -64,12 +64,10 @@ class HistoryHolder(
 
         // Set cover
         GlideApp.with(itemView.context).clear(cover)
-        if (!manga.thumbnail_url.isNullOrEmpty()) {
-            GlideApp.with(itemView.context)
-                .load(manga.toMangaThumbnail())
-                .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
-                .centerCrop()
-                .into(cover)
-        }
+        GlideApp.with(itemView.context)
+            .load(manga.toMangaThumbnail())
+            .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
+            .centerCrop()
+            .into(cover)
     }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/recent/updates/UpdatesHolder.kt

@@ -56,13 +56,11 @@ class UpdatesHolder(private val view: View, private val adapter: UpdatesAdapter)
 
         // Set cover
         GlideApp.with(itemView.context).clear(manga_cover)
-        if (!item.manga.thumbnail_url.isNullOrEmpty()) {
-            GlideApp.with(itemView.context)
-                .load(item.manga.toMangaThumbnail())
-                .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
-                .circleCrop()
-                .into(manga_cover)
-        }
+        GlideApp.with(itemView.context)
+            .load(item.manga.toMangaThumbnail())
+            .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
+            .circleCrop()
+            .into(manga_cover)
 
         // Check if chapter is read and set correct color
         if (item.chapter.read) {