Adds "Add Reagent" admin verb.

Content.Shared/Administration/AdminAddReagentEuiState.cs

@@ -0,0 +1,31 @@
+using System;
+using Content.Shared.Chemistry;
+using Content.Shared.Eui;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Administration
+{
+    [Serializable, NetSerializable]
+    public sealed class AdminAddReagentEuiState : EuiStateBase
+    {
+        public ReagentUnit MaxVolume;
+        public ReagentUnit CurVolume;
+    }
+
+    public static class AdminAddReagentEuiMsg
+    {
+        [Serializable, NetSerializable]
+        public sealed class Close : EuiMessageBase
+        {
+
+        }
+
+        [Serializable, NetSerializable]
+        public sealed class DoAdd : EuiMessageBase
+        {
+            public bool CloseAfter;
+            public ReagentUnit Amount;
+            public string ReagentId;
+        }
+    }
+}