Actions System + UI (#2710)

Co-authored-by: Vera Aguilera Puerto <6766154+Zumorica@users.noreply.github.com>

Content.Shared/Actions/ITargetPointAction.cs

@@ -0,0 +1,33 @@
+using System;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Map;
+
+namespace Content.Shared.Actions
+{
+    /// <summary>
+    /// Action which requires the user to select a target point, which
+    /// does not necessarily have an entity on it.
+    /// </summary>
+    public interface ITargetPointAction : IActionBehavior
+    {
+        /// <summary>
+        /// Invoked when the target point action should be performed.
+        /// Implementation should perform the server side logic of the action.
+        /// </summary>
+        void DoTargetPointAction(TargetPointActionEventArgs args);
+    }
+
+    public class TargetPointActionEventArgs : ActionEventArgs
+    {
+        /// <summary>
+        /// Local coordinates of the targeted position.
+        /// </summary>
+        public readonly EntityCoordinates Target;
+
+        public TargetPointActionEventArgs(IEntity performer, EntityCoordinates target, ActionType actionType)
+            : base(performer, actionType)
+        {
+            Target = target;
+        }
+    }
+}