Feature/local metadata more tags (#832)

* Stashing code

* removed some debug code on series detail page. Now detail is collapsed by default.

* Added AgeRating

* Fixed a crash when NetVips tries to write a cover file and cover directory is not existing.

* When a card is selected for bulk actions, show an outline in addition to select box

* Added AgeRating into the metadata parsing. Added a hack where ComicInfo uses Number in ComicInfo rather than Volume. This is to test out the effects on users libraries.

* Added AgeRating and ReleaseDate to the metadata implelentation.

API/Data/Migrations/20211205185207_MetadataAgeRating.cs

@@ -0,0 +1,26 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace API.Data.Migrations
+{
+    public partial class MetadataAgeRating : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "AgeRating",
+                table: "SeriesMetadata",
+                type: "INTEGER",
+                nullable: false,
+                defaultValue: 0);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "AgeRating",
+                table: "SeriesMetadata");
+        }
+    }
+}