Pass bindable to BeatmapMetadataDisplay

It was reported that mods selected in song select would show up during
loading of replays which were recorded under a different set of mods.
This was caused by BeatmapMetadataDisplay accepting a plain read-only
value of the Mods bindable in PlayerLoader.load(), therefore making the
mod value assignment in ReplayPlayerLoader.OnEntering() have no effect
on that component.

To resolve this issue, make BeatmapMetadataDisplay accept the
higher-level bindable, bind to it locally and pass it down the hierarchy
to ModDisplay.

osu.Game.Tests/Visual/Gameplay/TestScenePlayerLoader.cs

@@ -233,7 +233,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             public new Task DisposalTask => base.DisposalTask;
 
-            public IReadOnlyList<Mod> DisplayedMods => MetadataInfo.Mods;
+            public IReadOnlyList<Mod> DisplayedMods => MetadataInfo.Mods.Value;
 
             public TestPlayerLoader(Func<Player> createPlayer)
                 : base(createPlayer)