Feature/improve add to library category selection dialog (#631)

* Create "Categories" util class

* Only show add to library category selection in case categories exist

* Add edit categories button in select categories dialog

* Add option to disable add to library dialog to the dialog

src/lib/data/Categories.ts

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { TCategory } from '@/typings.ts';
+
+export const DEFAULT_CATEGORY_ID = 0;
+
+export type CategoryIdInfo = Pick<TCategory, 'id'>;
+export type CategoryDefaultInfo = Pick<TCategory, 'default'>;
+
+export class Categories {
+    static getIds(categories: CategoryIdInfo[]): number[] {
+        return categories.map((category) => category.id);
+    }
+
+    static getUserCreated<Category extends CategoryIdInfo>(categories: Category[]): Category[] {
+        return categories.filter((category) => category.id !== DEFAULT_CATEGORY_ID);
+    }
+
+    static getDefaults<Category extends CategoryDefaultInfo>(categories: Category[]): Category[] {
+        return categories.filter((category) => category.default);
+    }
+}