Find video by recursive check rather than marker interface

Seems a lot more reliable, and allows falling back to the "main" video
in cases which didn't support this previously.

A next step may be to allow every screen to support a video based on its
screen name, rather than specifying the local `TourneyVideo` every time.

osu.Game.Tournament/Components/TourneyVideo.cs

@@ -22,6 +22,8 @@ namespace osu.Game.Tournament.Components
         private Video video;
         private ManualClock manualClock;
 
+        public bool VideoAvailable => video != null;
+
         public TourneyVideo(string filename, bool drawFallbackGradient = false)
         {
             this.filename = filename;

osu.Game.Tournament/Screens/Drawings/DrawingsScreen.cs

@@ -24,7 +24,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Drawings
 {
-    public class DrawingsScreen : TournamentScreen, IProvideVideo
+    public class DrawingsScreen : TournamentScreen
     {
         private const string results_filename = "drawings_results.txt";
 

osu.Game.Tournament/Screens/Editors/TournamentEditorScreen.cs

@@ -20,7 +20,7 @@ using osuTK;
 
 namespace osu.Game.Tournament.Screens.Editors
 {
-    public abstract class TournamentEditorScreen<TDrawable, TModel> : TournamentScreen, IProvideVideo
+    public abstract class TournamentEditorScreen<TDrawable, TModel> : TournamentScreen
         where TDrawable : Drawable, IModelBacked<TModel>
         where TModel : class, new()
     {

osu.Game.Tournament/Screens/Gameplay/GameplayScreen.cs

@@ -21,7 +21,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Gameplay
 {
-    public class GameplayScreen : BeatmapInfoScreen, IProvideVideo
+    public class GameplayScreen : BeatmapInfoScreen
     {
         private readonly BindableBool warmup = new BindableBool();
 

osu.Game.Tournament/Screens/IProvideVideo.cs

@@ -1,14 +0,0 @@
-// 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.
-
-#nullable disable
-
-namespace osu.Game.Tournament.Screens
-{
-    /// <summary>
-    /// Marker interface for a screen which provides its own local video background.
-    /// </summary>
-    public interface IProvideVideo
-    {
-    }
-}

osu.Game.Tournament/Screens/Ladder/LadderScreen.cs

@@ -19,7 +19,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Ladder
 {
-    public class LadderScreen : TournamentScreen, IProvideVideo
+    public class LadderScreen : TournamentScreen
     {
         protected Container<DrawableTournamentMatch> MatchesContainer;
         private Container<Path> paths;

osu.Game.Tournament/Screens/Schedule/ScheduleScreen.cs

@@ -19,7 +19,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Schedule
 {
-    public class ScheduleScreen : TournamentScreen // IProvidesVideo
+    public class ScheduleScreen : TournamentScreen
     {
         private readonly Bindable<TournamentMatch> currentMatch = new Bindable<TournamentMatch>();
         private Container mainContainer;

osu.Game.Tournament/Screens/Setup/SetupScreen.cs

@@ -19,7 +19,7 @@ using osuTK;
 
 namespace osu.Game.Tournament.Screens.Setup
 {
-    public class SetupScreen : TournamentScreen, IProvideVideo
+    public class SetupScreen : TournamentScreen
     {
         private FillFlowContainer fillFlow;
 

osu.Game.Tournament/Screens/Showcase/ShowcaseScreen.cs

@@ -14,7 +14,7 @@ using osuTK.Graphics;
 
 namespace osu.Game.Tournament.Screens.Showcase
 {
-    public class ShowcaseScreen : BeatmapInfoScreen // IProvideVideo
+    public class ShowcaseScreen : BeatmapInfoScreen
     {
         [BackgroundDependencyLoader]
         private void load()

osu.Game.Tournament/Screens/TeamIntro/SeedingScreen.cs

@@ -19,7 +19,7 @@ using osuTK;
 
 namespace osu.Game.Tournament.Screens.TeamIntro
 {
-    public class SeedingScreen : TournamentMatchScreen, IProvideVideo
+    public class SeedingScreen : TournamentMatchScreen
     {
         private Container mainContainer;
 

osu.Game.Tournament/Screens/TeamIntro/TeamIntroScreen.cs

@@ -13,7 +13,7 @@ using osuTK;
 
 namespace osu.Game.Tournament.Screens.TeamIntro
 {
-    public class TeamIntroScreen : TournamentMatchScreen, IProvideVideo
+    public class TeamIntroScreen : TournamentMatchScreen
     {
         private Container mainContainer;
 

osu.Game.Tournament/Screens/TeamWin/TeamWinScreen.cs

@@ -14,7 +14,7 @@ using osuTK;
 
 namespace osu.Game.Tournament.Screens.TeamWin
 {
-    public class TeamWinScreen : TournamentMatchScreen, IProvideVideo
+    public class TeamWinScreen : TournamentMatchScreen
     {
         private Container mainContainer;
 

osu.Game.Tournament/TournamentSceneManager.cs

@@ -10,6 +10,7 @@ using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Input.Events;
+using osu.Framework.Testing;
 using osu.Framework.Threading;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
@@ -186,7 +187,7 @@ namespace osu.Game.Tournament
             var lastScreen = currentScreen;
             currentScreen = target;
 
-            if (currentScreen is IProvideVideo)
+            if (currentScreen.ChildrenOfType<TourneyVideo>().FirstOrDefault()?.VideoAvailable == true)
             {
                 video.FadeOut(200);