Voting (#3185)

* Basic voting

* Rewrite lobby in XAML.
Working lobby voting.

* Escape menu is now XAML.

* Vote menu works, custom votes, gamemode votes.

* Vote timeouts & administration.

Basically done now.

* I will now pretend I was never planning to code voting hotkeys.

* Make vote call UI a bit... funny.

* Fix exception on round restart.

* Fix some vote command definitions.

Content.Server/Voting/VoteFinishedEventArgs.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Immutable;
+
+#nullable enable
+
+namespace Content.Server.Voting
+{
+    public sealed class VoteFinishedEventArgs : EventArgs
+    {
+        /// <summary>
+        ///     Null if stalemate.
+        /// </summary>
+        public readonly object? Winner;
+
+        /// <summary>
+        ///     Winners. More than one if there was a stalemate.
+        /// </summary>
+        public readonly ImmutableArray<object> Winners;
+
+        public VoteFinishedEventArgs(object? winner, ImmutableArray<object> winners)
+        {
+            Winner = winner;
+            Winners = winners;
+        }
+    }
+}