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);
```

2 files changed, 3 insertions, 12 deletions

diff --git a/Emby.Server.Implementations/Net/SocketFactory.cs b/Emby.Server.Implementations/Net/SocketFactory.cs
index 21795c8f8..303875df5 100644
--- a/Emby.Server.Implementations/Net/SocketFactory.cs
+++ b/Emby.Server.Implementations/Net/SocketFactory.cs
@@ -63,10 +63,7 @@ namespace Emby.Server.Implementations.Net
         /// <inheritdoc />
         public ISocket CreateUdpMulticastSocket(IPAddress ipAddress, int multicastTimeToLive, int localPort)
         {
-            if (ipAddress == null)
-            {
-                throw new ArgumentNullException(nameof(ipAddress));
-            }
+            ArgumentNullException.ThrowIfNull(ipAddress);
 
             if (multicastTimeToLive <= 0)
             {
diff --git a/Emby.Server.Implementations/Net/UdpSocket.cs b/Emby.Server.Implementations/Net/UdpSocket.cs
index 2c20daa57..c3994fc04 100644
--- a/Emby.Server.Implementations/Net/UdpSocket.cs
+++ b/Emby.Server.Implementations/Net/UdpSocket.cs
@@ -35,10 +35,7 @@ namespace Emby.Server.Implementations.Net
 
         public UdpSocket(Socket socket, int localPort, IPAddress ip)
         {
-            if (socket == null)
-            {
-                throw new ArgumentNullException(nameof(socket));
-            }
+            ArgumentNullException.ThrowIfNull(socket);
 
             _socket = socket;
             _localPort = localPort;
@@ -51,10 +48,7 @@ namespace Emby.Server.Implementations.Net
 
         public UdpSocket(Socket socket, IPEndPoint endPoint)
         {
-            if (socket == null)
-            {
-                throw new ArgumentNullException(nameof(socket));
-            }
+            ArgumentNullException.ThrowIfNull(socket);
 
             _socket = socket;
             _socket.Connect(endPoint);