Make RestType handling case-insensitive in switch

Convert RestType to uppercase in the switch statement to
ensure case-insensitive matching of REST types. This change
handles variations like "get", "Get", and "GET" consistently.
Additionally, use the null-conditional operator to prevent
NullReferenceException when RestType is null.

src/ReC.Application/RecActions/Commands/InvokeRecActionCommand.cs

@@ -26,7 +26,7 @@ public class InvokeRecActionCommandHandler(ISender sender) : IRequestHandler<Inv
             using var http = new HttpClient();
             using var response = await http.GetAsync("https://example.com", cancel);
 
-            switch (action.RestType)
+            switch (action.RestType?.ToUpper().Trim())
             {
                 case "GET":
                     // Handle GET