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);
```

Emby.Server.Implementations/Updates/InstallationManager.cs

@@ -294,10 +294,7 @@ namespace Emby.Server.Implementations.Updates
         /// <inheritdoc />
         public async Task InstallPackage(InstallationInfo package, CancellationToken cancellationToken)
         {
-            if (package == null)
-            {
-                throw new ArgumentNullException(nameof(package));
-            }
+            ArgumentNullException.ThrowIfNull(package);
 
             var innerCancellationTokenSource = new CancellationTokenSource();