Adds Handheld Radio/Listener system (#1457)

* re-do of old PR that got fuckied upp

* simplify foreach as suggested

* pass distance to PassSpeechData for a check, remove GetListenRange()

* adds RadioQuery instead of subscribing/unsubscribing

* change SpreadMessage to accept owner rather than component

* change RadioQuery to EntityQuery

* remove declared EntityQuery (oops, didn't know what shadowcommander meant)

* refactor ListeningSystem & refactor added chat logic into listen sys

* IGNORE the oopsie STOP LOOKING

Content.Server/Interfaces/IListen.cs

@@ -0,0 +1,17 @@
+using Robust.Shared.Interfaces.GameObjects;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Content.Server.Interfaces
+{
+    /// <summary>
+    ///     Interface for objects such as radios meant to have an effect when speech is heard.
+    /// </summary>
+    public interface IListen
+    {
+        void HeardSpeech(string speech, IEntity source);
+
+        int GetListenRange();
+    }
+}