Book Reading Progress Enhancement (#259)

* Added book reader reading direction preference

* Adds a new marker to the AppUserProgress to capture nearest anchor for resuming scroll point when reading books. Refactored bookmark api to return a BookmarkDto which includes this new data.

API/Data/Migrations/20210603212429_BookScrollIdProgress.cs

@@ -0,0 +1,23 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+namespace API.Data.Migrations
+{
+    public partial class BookScrollIdProgress : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "BookScrollId",
+                table: "AppUserProgresses",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "BookScrollId",
+                table: "AppUserProgresses");
+        }
+    }
+}