Detect identical mangas when adding to library (#6579)

* added duplicate manga check

When adding a manga to your library, the app will go through each manga previously added and compare their names. If a match is detected, it will prompt the user and ask for confirmation. On this prompt there is also an option to view the other manga.

* added german translations for newly added strings

* Revert "added german translations for newly added strings"

This reverts commit 71ada620671651daeeb2546aecd02400a4bc86bc.

* changed `AlertDialog.Builder` to `MaterialAlertDialogBuilder`

* using SQL query instead of filtering entire library with Kotlin

app/src/main/java/eu/kanade/tachiyomi/data/database/queries/MangaQueries.kt

@@ -34,6 +34,21 @@ interface MangaQueries : DbProvider {
         .withGetResolver(LibraryMangaGetResolver.INSTANCE)
         .prepare()
 
+    fun getDuplicateLibraryManga(manga: Manga) = db.get()
+        .`object`(Manga::class.java)
+        .withQuery(
+            Query.builder()
+                .table(MangaTable.TABLE)
+                .where("${MangaTable.COL_FAVORITE} = 1 AND LOWER(${MangaTable.COL_TITLE}) = ? AND ${MangaTable.COL_SOURCE} != ?")
+                .whereArgs(
+                    manga.title.lowercase(),
+                    manga.source,
+                )
+                .limit(1)
+                .build()
+        )
+        .prepare()
+
     fun getFavoriteMangas(sortByTitle: Boolean = true): PreparedGetListOfObjects<Manga> {
         var queryBuilder = Query.builder()
             .table(MangaTable.TABLE)