Fix & extend add reagent verb (#4954)

* AddReagentWindow

* addReagent command

* functional UI

* fix networking

* add comments & docstrings

* Remove unecesary system

* cleanup & close-eui

* tweak default window size

* fix EUI closing error

* fix merge issues

* fix merge

Content.Shared/Administration/EditSolutionsEuiState.cs

@@ -0,0 +1,28 @@
+using Content.Shared.Eui;
+using Robust.Shared.Serialization;
+using System;
+using Robust.Shared.GameObjects;
+using System.Collections.Generic;
+using Content.Shared.Chemistry.Components;
+
+namespace Content.Shared.Administration
+{
+    [Serializable, NetSerializable]
+    public class EditSolutionsEuiState : EuiStateBase
+    {
+        public readonly EntityUid Target;
+        public readonly Dictionary<string, Solution>? Solutions;
+
+        public EditSolutionsEuiState(EntityUid target, Dictionary<string, Solution>? solutions)
+        {
+            Target = target;
+            Solutions = solutions;
+        }
+    }
+
+    public static class EditSolutionsEuiMsg
+    {
+        [Serializable, NetSerializable]
+        public sealed class Close : EuiMessageBase { }
+    }
+}