Remove dotnet-ef tool config and IIS publish profiles

Deleted dotnet-tools.json (dotnet-ef config) and IIS publish profiles for .NET 7 and .NET 9 (IISProfileNet7Win64.pubxml, IISProfileNet9Win64.pubxml) to clean up unused deployment and tooling files.

EnvelopeGenerator.API/Models/ConnectionString.cs

@@ -0,0 +1,12 @@
+namespace EnvelopeGenerator.GeneratorAPI.Models;
+
+/// <summary>
+/// 
+/// </summary>
+public class ConnectionString
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public string Value { get; set; } = string.Empty;
+}