Add user to AttemptMeleeEvent, add ThrowItemAttemptEvent (#30193)

* Add user to AttemptMeleeEvent, add ThrowItemAttemptEvent

* Add xmldoc

Content.Shared/Throwing/ThrowAttemptEvent.cs

@@ -13,6 +13,14 @@
         public EntityUid ItemUid { get; }
     }
 
+    /// <summary>
+    ///     Raised on the item entity that is thrown.
+    /// </summary>
+    /// <param name="User">The user that threw this entity.</param>
+    /// <param name="Cancelled">Whether or not the throw should be cancelled.</param>
+    [ByRefEvent]
+    public record struct ThrowItemAttemptEvent(EntityUid User, bool Cancelled = false);
+
     /// <summary>
     /// Raised when we try to pushback an entity from throwing
     /// </summary>