Weldable cleanup (#19809)

Content.Shared/Tools/Systems/WeldableAttemptEvent.cs

@@ -0,0 +1,17 @@
+namespace Content.Shared.Tools.Systems;
+
+/// <summary>
+///     Checks that entity can be weld/unweld.
+///     Raised twice: before do_after and after to check that entity still valid.
+/// </summary>
+public sealed class WeldableAttemptEvent : CancellableEntityEventArgs
+{
+    public readonly EntityUid User;
+    public readonly EntityUid Tool;
+
+    public WeldableAttemptEvent(EntityUid user, EntityUid tool)
+    {
+        User = user;
+        Tool = tool;
+    }
+}