Add HasValidInstrument property to YargProfile (YARC-Official#209)

* Add HasValidInstrument property to YargProfile

* Applied PR review changes
Introduced EnsureValidInstrument() to YARG.Core
Applied style change to several one-liner if statements

YARG.Core/Game/YargProfile.cs

@@ -4,6 +4,7 @@
 using YARG.Core.Chart;
 using YARG.Core.Utility;
 using YARG.Core.Extensions;
+using System.Linq;
 
 namespace YARG.Core.Game
 {
@@ -32,6 +33,8 @@ public double InputCalibrationSeconds
             set => InputCalibrationMilliseconds = (long) (value * 1000);
         }
 
+        public bool HasValidInstrument => GameMode.PossibleInstruments().Contains(CurrentInstrument);
+
         public Guid EnginePreset;
 
         public Guid ThemePreset;
@@ -175,6 +178,15 @@ public void ApplyVocalModifiers(VocalsPart vocalsPart)
             }
         }
 
+        public void EnsureValidInstrument()
+        {
+
+            if (!HasValidInstrument)
+            {
+                CurrentInstrument = GameMode.PossibleInstruments()[0];
+            }
+        }
+
         // For replay serialization
         public void Serialize(BinaryWriter writer)
         {