feat!: support only .NET Framework 4.7.2

In order to conform with the plugin format and the workflow, the .csproj
file was moved up a level to the root of the `src` folder and the
solution file was renamed.

Workflows were also changed to match the plugin workflows.

BREAKING CHANGE: Supports ONLY .NET Framework 4.7.2

src/CoreInterfaces.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Crestron.SimplSharp;
+using Serilog;
+
+namespace PepperDash.Core
+{
+    /// <summary>
+    /// Unique key interface to require a unique key for the class
+    /// </summary>
+	public interface IKeyed
+	{
+        /// <summary>
+        /// Unique Key
+        /// </summary>
+		string Key { get; }
+    }
+
+    /// <summary>
+    /// Named Keyed device interface. Forces the device to have a Unique Key and a name. 
+    /// </summary>
+	public interface IKeyName : IKeyed
+    {
+        /// <summary>
+        /// Isn't it obvious :)
+        /// </summary>
+		string Name { get; }
+    }
+
+}