Code formatting updates (#4502)

* Editorconfig: Add space_before_self_closing setting

This was a difference between the way dotnet-format and Rider format code. See https://www.jetbrains.com/help/rider/EditorConfig_Index.html

* Editorconfig: Keep 4 spaces indentation for Swagger JSON files

They are all formatted that way, let's keep it like that.

* Apply dotnet-format, mostly white-space related changes

BTCPayServer/Controllers/UIPaymentRequestController.cs

@@ -88,7 +88,7 @@ namespace BTCPayServer.Controllers
                     AmountFormatted = _Currencies.FormatCurrency(blob.Amount, blob.Currency)
                 };
             }).ToList();
-            
+
             return View(model);
         }
 
@@ -150,7 +150,7 @@ namespace BTCPayServer.Controllers
                 return View(nameof(EditPaymentRequest), viewModel);
             }
 
-            
+
             blob.Title = viewModel.Title;
             blob.Email = viewModel.Email;
             blob.Description = viewModel.Description;
@@ -239,7 +239,7 @@ namespace BTCPayServer.Controllers
                 }
             });
         }
-        
+
         [HttpGet("{payReqId}/pay")]
         [AllowAnonymous]
         public async Task<IActionResult> PayPaymentRequest(string payReqId, bool redirectToInvoice = true,