Add prototype serialization tests. (#18458)

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Shared/Nutrition/Flavor.cs

@@ -0,0 +1,22 @@
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.Nutrition;
+
+[Prototype("flavor")]
+public sealed class FlavorPrototype : IPrototype
+{
+    [IdDataField]
+    public string ID { get; } = default!;
+
+    [DataField("flavorType")]
+    public FlavorType FlavorType { get; } = FlavorType.Base;
+
+    [DataField("description")]
+    public string FlavorDescription { get; } = default!;
+}
+
+public enum FlavorType : byte
+{
+    Base,
+    Complex
+}