Refactor NpTicket parser and add NpTicket signature documentation (#784)

* Refactor NpTicket parser and add NpTicket signature documentation

* Update TickerBuilder chaining style

* Fix SectionHeader position returning wrong value

* Don't attempt to parse ticket if it is less than 8 bytes

ProjectLighthouse.Tests/Unit/TicketTests.cs

@@ -0,0 +1,48 @@
+using LBPUnion.ProjectLighthouse.Tickets;
+using LBPUnion.ProjectLighthouse.Tickets.Signature;
+using LBPUnion.ProjectLighthouse.Types.Users;
+using Xunit;
+
+namespace LBPUnion.ProjectLighthouse.Tests.Unit;
+
+[Trait("Category", "Unit")]
+public class TicketTests
+{
+    [Fact]
+    public void CanReadTicket()
+    {
+        TicketBuilder builder = new TicketBuilder()
+            .SetCountry("br")
+            .SetUserId(21)
+            .SetDomain("us")
+            .SetStatus(0)
+            .SetIssuerId(0x74657374)
+            .setExpirationTime(ulong.MaxValue)
+            .SetUsername("unittest")
+            .SetIssueTime(0)
+            .SetTitleId("UP9000-BCUS98245_00");
+
+        byte[] ticketData = builder.Build();
+
+        NPTicket? ticket = NPTicket.CreateFromBytes(ticketData);
+        Assert.NotNull(ticket);
+        Assert.Equal((ulong)0, ticket.IssueTime);
+        Assert.Equal(ulong.MaxValue, ticket.ExpireTime);
+        Assert.Equal("unittest", ticket.Username);
+        Assert.Equal(GameVersion.LittleBigPlanet2, ticket.GameVersion);
+        Assert.Equal((ulong)0x74657374, ticket.IssuerId);
+        Assert.Equal((ulong)21, ticket.UserId);
+    }
+
+    [Fact]
+    public void CanVerifyTicketSignature()
+    {
+        TicketBuilder builder = new();
+
+        byte[] ticketData = builder.Build();
+
+        NPTicket? ticket = NPTicket.CreateFromBytes(ticketData);
+        Assert.NotNull(ticket);
+        Assert.True(new UnitTestSignatureVerifier(ticket).ValidateSignature());
+    }
+}