Add new Backend structure with proper .NET 8 projects

src/Backend/DiunaBI.WebAPI/Controllers/AdminController.cs

@@ -0,0 +1,28 @@
+using System.Data;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.SqlClient;
+using DiunaBI.Core.Models;
+
+namespace DiunaBI.Core.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class AdminController : Controller
+{
+
+    private readonly IConfiguration _configuration;
+
+    public AdminController(
+        IConfiguration configuration)
+    {
+        _configuration = configuration;
+    }
+
+    [HttpGet]
+    [Route("Version")]
+    public IActionResult GetVersion()
+    {
+        return Ok(new { version = _configuration["app-version"] });
+    }
+}