Predict appraisal tool verb! (#32496)

* First commit

* Network :(

Content.Shared/Cargo/SharedPriceGunSystem.cs

@@ -0,0 +1,55 @@
+using Content.Shared.Cargo.Components;
+using Content.Shared.IdentityManagement;
+using Content.Shared.Interaction;
+using Content.Shared.Verbs;
+
+namespace Content.Shared.Cargo.Systems;
+
+/// <summary>
+///     The price gun system! If this component is on an entity, you can scan objects (Click or use verb) to see their price.
+/// </summary>
+public abstract class SharedPriceGunSystem : EntitySystem
+{
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<PriceGunComponent, GetVerbsEvent<UtilityVerb>>(OnUtilityVerb);
+        SubscribeLocalEvent<PriceGunComponent, AfterInteractEvent>(OnAfterInteract);
+    }
+
+    private void OnUtilityVerb(EntityUid uid, PriceGunComponent component, GetVerbsEvent<UtilityVerb> args)
+    {
+        if (!args.CanAccess || !args.CanInteract || args.Using == null)
+            return;
+
+        var verb = new UtilityVerb()
+        {
+            Act = () =>
+            {
+                GetPriceOrBounty(uid, args.Target, args.User);
+            },
+            Text = Loc.GetString("price-gun-verb-text"),
+            Message = Loc.GetString("price-gun-verb-message", ("object", Identity.Entity(args.Target, EntityManager)))
+        };
+
+        args.Verbs.Add(verb);
+    }
+
+    private void OnAfterInteract(Entity<PriceGunComponent> entity, ref AfterInteractEvent args)
+    {
+        if (!args.CanReach || args.Target == null || args.Handled)
+            return;
+
+        args.Handled |= GetPriceOrBounty(entity, args.Target.Value, args.User);
+    }
+
+    /// <summary>
+    ///     Find the price or confirm if the item is a bounty. Will give a popup of the result to the passed user.
+    /// </summary>
+    /// <returns></returns>
+    /// <remarks>
+    ///     This is abstract for prediction. When the bounty system / cargo systems that are necessary are moved to shared,
+    ///     combine all the server, client, and shared stuff into one non abstract file.
+    /// </remarks>
+    protected abstract bool GetPriceOrBounty(EntityUid priceGunUid, EntityUid target, EntityUid user);
+}