HUD Themes (#3774)

* HUD Themes

* Prototypes

* field

* oops

* ugh

* Fixes

* Update Content.Client/UserInterface/GameHud.cs

Co-authored-by: ike709 <sparebytes@protonmail.com>

Content.Shared/Prototypes/HUD/HudThemePrototype.cs

@@ -0,0 +1,18 @@
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Content.Shared.Prototypes.HUD
+{
+    [Prototype("hudTheme")]
+    public class HudThemePrototype : IPrototype
+    {
+        [field: DataField("name", required: true)]
+        public string Name { get; } = string.Empty;
+
+        [field: DataField("id", required: true)]
+        public string ID { get; } = string.Empty;
+
+        [field: DataField("path", required: true)]
+        public string Path { get; } = string.Empty;
+    }
+}