Fix all warnings: non-nullable properties, obsolete methods, and header handling

Co-authored-by: renemadsen <[email protected]>

Author: Copilot

eFormAPI/eFormAPI.Web/Controllers/Eforms/AudioController.cs

@@ -72,7 +72,7 @@ public async Task<IActionResult> GetAudio(string fileName)
             //    new MediaTypeHeaderValue("application/octet-stream");
             //result.Content.Headers.ContentLength = stream.Length;
             //result.Content.Headers.ContentRange = new ContentRangeHeaderValue(0, stream.Length);
-            Response.Headers.Add("Accept-Ranges", "bytes");
+            Response.Headers["Accept-Ranges"] = "bytes";
             Response.Headers.Remove("Cache-Control");
             return File(stream, "audio/wav");
         }

eFormAPI/eFormAPI.Web/Hosting/Security/ClaimsTransformer.cs

@@ -77,7 +77,7 @@ public async Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
 
         if (auth == null)
         {
-            _httpContextAccessor.HttpContext.Response.Headers.Add(AuthConsts.UpdateHeaderName, AuthConsts.UpdateHeaderValue);
+            _httpContextAccessor.HttpContext.Response.Headers[AuthConsts.UpdateHeaderName] = AuthConsts.UpdateHeaderValue;
         }
         else
         {
@@ -86,7 +86,7 @@ public async Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
 
             if (timeValue != auth.TimeStamp)
             {
-                _httpContextAccessor.HttpContext.Response.Headers.Add(AuthConsts.UpdateHeaderName, AuthConsts.UpdateHeaderValue);
+                _httpContextAccessor.HttpContext.Response.Headers[AuthConsts.UpdateHeaderName] = AuthConsts.UpdateHeaderValue;
             }
 
             // Add claims

eFormAPI/eFormAPI.Web/Infrastructure/Models/SelectableList/AdvEntitySelectableGroupEditModel.cs

@@ -31,8 +31,8 @@ namespace eFormAPI.Web.Infrastructure.Models.SelectableList;
 
 public class AdvEntitySelectableGroupEditModel
 {
-    public string Name { get; set; }
-    public string GroupUid { get; set; }
-    public string Description { get; set; }
+    public required string Name { get; set; }
+    public required string GroupUid { get; set; }
+    public required string Description { get; set; }
     public List<EntityItem>? EntityItemModels { get; set; }
 }

eFormAPI/eFormAPI.Web/Services/WordProcessor.cs

@@ -59,7 +59,7 @@ public void AddHtml(string html)
         }
 
         var converter = new HtmlConverter(mainPart);
-        converter.ParseHtml(html);
+        converter.ParseBody(html);
         mainPart.Document.Save();
     }