Add game preset attribute, unhardcode game presets (#3166)

* Add game preset attribute, unhardcode game presets

* Add game preset attribute doc

* Add preset attribute to extended

* Remove try methods from playerdata

Content.Server/GameTicking/GamePresets/GamePresetAttribute.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Immutable;
+using JetBrains.Annotations;
+
+namespace Content.Server.GameTicking.GamePresets
+{
+    /// <summary>
+    ///     Attribute that marks a game preset.
+    ///     The id and aliases are registered in lowercase in <see cref="GameTicker"/>.
+    ///     A duplicate id or alias will throw an exception.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class, Inherited = false)]
+    [BaseTypeRequired(typeof(GamePreset))]
+    [MeansImplicitUse]
+    public class GamePresetAttribute : Attribute
+    {
+        public string Id { get; }
+
+        public ImmutableList<string> Aliases { get; }
+
+        public GamePresetAttribute(string id, params string[] aliases)
+        {
+            Id = id;
+            Aliases = aliases.ToImmutableList();
+        }
+    }
+}