Image added (#434)

* Image added

* ImageMaximumBytes

* FileController remove Authorized

* ApplicationCore.Constants.AuthorizationConstants.AUTH_KEY

* SavePicture in the interface.

* IFileSystem in Core

* WebFileSystem in Infrastructure

* PictureUri removed from UpdateCatalogItemRequest

* Modal scroll fix

src/Web/Controllers/FileController.cs

@@ -0,0 +1,38 @@
+using System;
+using System.IO;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.eShopWeb.Web.ViewModels.File;
+
+namespace Microsoft.eShopWeb.Web.Controllers
+{
+    [Route("[controller]")]
+    [ApiController]
+    public class FileController : ControllerBase
+    {
+        [HttpPost]
+        [AllowAnonymous]
+        public IActionResult Upload(FileViewModel fileViewModel)
+        {
+            if (!Request.Headers.ContainsKey("auth-key") || Request.Headers["auth-key"].ToString() != ApplicationCore.Constants.AuthorizationConstants.AUTH_KEY)
+            {
+                return Unauthorized();
+            }
+
+            if(fileViewModel == null || string.IsNullOrEmpty(fileViewModel.DataBase64)) return BadRequest();
+
+            var fileData = Convert.FromBase64String(fileViewModel.DataBase64);
+            if (fileData.Length <= 0) return BadRequest();
+
+            var fullPath = Path.Combine(Directory.GetCurrentDirectory(), @"wwwroot/images/products", fileViewModel.FileName);
+            if (System.IO.File.Exists(fullPath))
+            {
+                System.IO.File.Delete(fullPath);
+            }
+            System.IO.File.WriteAllBytes(fullPath, fileData);
+
+            return Ok();
+        }
+        
+    }
+}