feat(embed): show skip-prev/next buttons in embed when queue exists

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerControls.razor

@@ -2,7 +2,7 @@
 @using DeepDrftPublic.Client.Controls
 
 <MudStack Row="true" AlignItems="AlignItems.Center" Spacing="2">
-    @if (!Fixed)
+    @if (!Fixed || HasPrevious || HasNext)
     {
         <MudIconButton Icon="@Icons.Material.Filled.SkipPrevious"
                        Color="Color.Primary"
@@ -14,13 +14,16 @@
                    Color="Color.Primary"
                    Disabled="!CanPlay"
                    OnToggle="@TogglePlayPause"/>
-    @if (!Fixed)
+    @if (!Fixed || HasPrevious || HasNext)
     {
         <MudIconButton Icon="@Icons.Material.Filled.SkipNext"
                        Color="Color.Primary"
                        Size="Size.Large"
                        OnClick="@SkipNext"
                        Disabled="!HasNext"/>
+    }
+    @if (!Fixed)
+    {
         <MudIconButton Icon="@Icons.Material.Filled.Stop"
                        Color="Color.Primary"
                        Size="Size.Large"