Add audio presence check

osu.Game/Rulesets/Edit/Checks/CheckAudioPresence.cs

@@ -0,0 +1,15 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit.Checks.Components;
+
+namespace osu.Game.Rulesets.Edit.Checks
+{
+    public class CheckAudioPresence : CheckFilePresence
+    {
+        protected override CheckCategory Category => CheckCategory.Audio;
+        protected override string TypeOfFile => "audio";
+        protected override string GetFilename(IWorkingBeatmap workingBeatmap) => workingBeatmap.Beatmap.Metadata?.AudioFile;
+    }
+}