feat: NetworkBehaviour/NetworkIdentity 'isHost' (#4047)

Author: miwarnec

Assets/Mirror/Core/NetworkBehaviour.cs

@@ -62,6 +62,9 @@ public abstract class NetworkBehaviour : MonoBehaviour
         /// <summary>True if this object is on the client and has been spawned by the server.</summary>
         public bool isClient => netIdentity.isClient;
 
+        /// <summary>Returns true for spawned objects in host mode.</summary>
+        public bool isHost => isServer && isClient;
+
         /// <summary>True if this object is the the client's own local player.</summary>
         public bool isLocalPlayer => netIdentity.isLocalPlayer;
 

Assets/Mirror/Core/NetworkIdentity.cs

@@ -88,6 +88,9 @@ public sealed class NetworkIdentity : MonoBehaviour
         //   => fixes https://github.com/vis2k/Mirror/issues/2533
         public bool isServer { get; internal set; }
 
+        /// <summary>Returns true for spawned objects in host mode.</summary>
+        public bool isHost => isServer && isClient;
+
         /// <summary>Return true if this object represents the player on the local machine.</summary>
         //
         // IMPORTANT: