Use ArgumentNullException.ThrowIfNull helper method

Did a simple search/replace on the whole repo (except the RSSDP project)
This reduces LOC and should improve performance (methods containing a throw statement don't get inlined)

```
if \((\w+) == null\)
\s+\{
\s+throw new ArgumentNullException\((.*)\);
\s+\}
```

```
ArgumentNullException.ThrowIfNull($1);
```

1 files changed, 2 insertions, 8 deletions

diff --git a/Emby.Server.Implementations/Sorting/IndexNumberComparer.cs b/Emby.Server.Implementations/Sorting/IndexNumberComparer.cs
index c5b00afb1..1bcaccd8a 100644
--- a/Emby.Server.Implementations/Sorting/IndexNumberComparer.cs
+++ b/Emby.Server.Implementations/Sorting/IndexNumberComparer.cs
@@ -24,15 +24,9 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.Int32.</returns>
         public int Compare(BaseItem? x, BaseItem? y)
         {
-            if (x == null)
-            {
-                throw new ArgumentNullException(nameof(x));
-            }
+            ArgumentNullException.ThrowIfNull(x);
 
-            if (y == null)
-            {
-                throw new ArgumentNullException(nameof(y));
-            }
+            ArgumentNullException.ThrowIfNull(y);
 
             if (!x.IndexNumber.HasValue && !y.IndexNumber.HasValue)
             {