Initial import of the CBDDC codebase with docs and tests. Add a .NET-focused gitignore to keep generated artifacts out of source control.

src/ZB.MOM.WW.CBDDC.Network/Security/IAuthenticator.cs

@@ -0,0 +1,14 @@
+using System.Threading.Tasks;
+
+namespace ZB.MOM.WW.CBDDC.Network.Security;
+
+public interface IAuthenticator
+{
+    /// <summary>
+    /// Validates an authentication token for a node identifier.
+    /// </summary>
+    /// <param name="nodeId">The node identifier to validate.</param>
+    /// <param name="token">The authentication token to validate.</param>
+    /// <returns><see langword="true"/> if the token is valid for the node; otherwise <see langword="false"/>.</returns>
+    Task<bool> ValidateAsync(string nodeId, string token);
+}