feat: move MC into Essentials

In order to solve some dependency issues that keep cropping up, MC
should be moved back into the Essentials repo and loaded automatically
on startup. This will allow for all plugins that use the MC Messengers
library to use the same version without fear of overwriting a dll due to
loading of plugin libraries.

src/PepperDash.Essentials.MobileControl/Touchpanel/ThemeMessenger.cs

@@ -0,0 +1,42 @@
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using PepperDash.Core;
+using PepperDash.Essentials.AppServer;
+using PepperDash.Essentials.AppServer.Messengers;
+
+namespace PepperDash.Essentials.Touchpanel
+{
+    public class ThemeMessenger : MessengerBase
+    {
+        private readonly ITheme _tpDevice;
+
+        public ThemeMessenger(string key, string path, ITheme device) : base(key, path, device as Device)
+        {
+            _tpDevice = device;
+        }
+
+        protected override void RegisterActions()
+        {
+            AddAction("/fullStatus", (id, content) =>
+            {
+                PostStatusMessage(new ThemeUpdateMessage { Theme = _tpDevice.Theme });
+            });
+
+            AddAction("/saveTheme", (id, content) =>
+            {
+                var theme = content.ToObject<MobileControlSimpleContent<string>>();
+
+                Debug.LogMessage(Serilog.Events.LogEventLevel.Information, "Setting theme to {theme}", this, theme.Value);
+                _tpDevice.UpdateTheme(theme.Value);            
+
+                PostStatusMessage(JToken.FromObject(new {theme =  theme.Value}));
+            });
+        }
+    }
+
+    public class ThemeUpdateMessage:DeviceStateMessageBase
+    {
+        [JsonProperty("theme")]
+        public string Theme { get; set; }
+    }
+}