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, 3 insertions, 9 deletions

diff --git a/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs b/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
index a81f78ebfc..ce44f99a69 100644
--- a/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
+++ b/Emby.Server.Implementations/Sorting/OfficialRatingComparer.cs
@@ -31,15 +31,9 @@ namespace Emby.Server.Implementations.Sorting
         /// <returns>System.Int32.</returns>
         public int Compare(BaseItem? x, BaseItem? y)
         {
-            if (x == null)
-            {
-                throw new ArgumentNullException(nameof(x));
-            }
-
-            if (y == null)
-            {
-                throw new ArgumentNullException(nameof(y));
-            }
+            ArgumentNullException.ThrowIfNull(x);
+
+            ArgumentNullException.ThrowIfNull(y);
 
             var levelX = string.IsNullOrEmpty(x.OfficialRating) ? 0 : _localization.GetRatingLevel(x.OfficialRating) ?? 0;
             var levelY = string.IsNullOrEmpty(y.OfficialRating) ? 0 : _localization.GetRatingLevel(y.OfficialRating) ?? 0;