Update to NetCore 3.1, added Kestrel for REST api and few basic endpoints.

ASS.Server/Web/Startup.cs

@@ -0,0 +1,48 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace ASS.Server.Web
+{
+    class Startup
+    {
+
+        public Startup(IConfiguration configuration)
+        {
+            Configuration = configuration;
+        }
+
+        public IConfiguration Configuration { get; }
+
+        // This method gets called by the runtime. Use this method to add services to the container.
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddControllers();
+        }
+
+        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            app.UseHttpsRedirection();
+
+            app.UseRouting();
+
+            //app.UseAuthorization();
+
+            app.UseEndpoints(endpoints =>
+            {
+                endpoints.MapControllers();
+            });
+        }
+    }
+}