Fix IModuleInitializer.Initialize not being called

src/gaemstone.SourceGen/ModuleGenerator.cs

@@ -132,6 +132,9 @@ public class ModuleGenerator
 
 		// TODO: Can BuiltIn modules have systems and such?
 
+		if (module.HasInitializer)
+			sb.AppendLine("\t\tInitialize(module);");
+
 		sb.AppendLine("\t}");
 
 		sb.AppendLine("}");

src/gaemstone.SourceGen/Structure/MethodEntityInfo.cs

@@ -25,6 +25,8 @@ public class MethodEntityInfo : BaseEntityInfo
 	public bool HasPhaseSet { get; private set; }
 	public override bool HasEntitiesToAdd => base.HasEntitiesToAdd || !HasPhaseSet;
 
+	// TODO: Support [Source].
+
 	public MethodEntityInfo(ISymbol symbol)
 		: base(symbol)
 	{

src/gaemstone.SourceGen/Structure/ModuleEntityInfo.cs

@@ -11,15 +11,18 @@ public class ModuleEntityInfo : TypeEntityInfo
 {
 	public bool IsPartial { get; }
 	public bool IsBuiltIn { get; }
-
-	// TODO: Support [Source].
+	public bool HasInitializer { get; }
 
 	public ModuleEntityInfo(ISymbol symbol)
 		: base(symbol)
 	{
 		var classDecl = (TypeDeclarationSyntax)Symbol.DeclaringSyntaxReferences.First().GetSyntax();
 		IsPartial = classDecl.Modifiers.Any(t => t.IsKind(SyntaxKind.PartialKeyword));
+
 		IsBuiltIn = Has("BuiltIn");
+
+		HasInitializer = Symbol.AllInterfaces.Any(i =>
+			i.GetFullName(FullNameStyle.NoGeneric) == "gaemstone.ECS.IModuleInitializer");
 	}
 
 	protected override IEnumerable<Diagnostic> ValidateSelf()