fix(core): Converts book packets (#413)

- [X] Splits out BaseBook
- [X] Converts book packets
- [X] Makes FixHtml faster

Projects/UOContent.Tests/Tests/Items/Books/BookPacketTests.cs

@@ -0,0 +1,67 @@
+using System;
+using Server;
+using Server.Items;
+using Server.Network;
+using Server.Tests;
+using Server.Tests.Network;
+using Xunit;
+
+namespace UOContent.Tests
+{
+    public class BookPacketTests : IClassFixture<ServerFixture>
+    {
+        [Theory]
+        [InlineData("🅵🅰🅽🅲🆈 🆃🅴🆇🆃 Author", "🅵🅰🅽🅲🆈 🆃🅴🆇🆃 Title")]
+        public void TestBookCover(string author, string title)
+        {
+            var m = new Mobile(0x1);
+            m.DefaultMobileInit();
+
+            var book = new BlueBook { Author = author, Title = title };
+
+            var expected = new BookHeader(m, book).Compile();
+
+            using var ns = PacketTestUtilities.CreateTestNetState();
+            ns.SendBookCover(m, book);
+
+            var result = ns.SendPipe.Reader.TryRead();
+            AssertThat.Equal(result.Buffer[0].AsSpan(0), expected);
+        }
+
+        [Fact]
+        public void TestBookContent()
+        {
+            var m = new Mobile(0x1);
+            m.DefaultMobileInit();
+
+            var book = new BlueBook { Author = "Some Author", Title = "Some Title" };
+            book.Pages[0].Lines = new[]
+            {
+                "Some books start with actual content",
+                "This book does not have any actual content",
+                "Instead it has several pages of useless text"
+            };
+
+            book.Pages[1].Lines = new[]
+            {
+                "Another page exists but this page:",
+                "Has lots of: 🅵🅰🅽🅲🆈 🆃🅴🆇🆃",
+                "And just more: 🅵🅰🅽🅲🆈 🆃🅴🆇🆃",
+                "So everyone can read: 🅵🅰🅽🅲🆈 🆃🅴🆇🆃"
+            };
+
+            book.Pages[2].Lines = new[]
+            {
+                "The end"
+            };
+
+            var expected = new BookPageDetails(book).Compile();
+
+            using var ns = PacketTestUtilities.CreateTestNetState();
+            ns.SendBookContent(book);
+
+            var result = ns.SendPipe.Reader.TryRead();
+            AssertThat.Equal(result.Buffer[0].AsSpan(0), expected);
+        }
+    }
+}