Add UI for setting solution transfer amount (#4074)

* basic eui and window

* finish EUI, update defaults

* unnecessary usings

* convert to bounduserinterface

* merge me up

merge me up inside

* Fix repeated define for component in prototype

* impl swept UI suggestion

* apply discord reviews

* small changes

Content.Shared/Chemistry/SharedTransferAmount.cs

@@ -0,0 +1,37 @@
+using System;
+using Content.Shared.Chemistry.Reagent;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Chemistry
+{
+    [Serializable, NetSerializable]
+    public class TransferAmountBoundInterfaceState : BoundUserInterfaceState
+    {
+        public ReagentUnit Max;
+        public ReagentUnit Min;
+
+        public TransferAmountBoundInterfaceState(ReagentUnit max, ReagentUnit min)
+        {
+            Max = max;
+            Min = min;
+        }
+    }
+
+    [Serializable, NetSerializable]
+    public class TransferAmountSetValueMessage : BoundUserInterfaceMessage
+    {
+        public ReagentUnit Value;
+
+        public TransferAmountSetValueMessage(ReagentUnit value)
+        {
+            Value = value;
+        }
+    }
+
+    [Serializable, NetSerializable]
+    public enum TransferAmountUiKey
+    {
+        Key,
+    }
+}