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/Models/WalletViewModels/WalletSendVaultModel.cs

@@ -6,6 +6,6 @@ namespace BTCPayServer.Models.WalletViewModels
         public string WebsocketPath { get; set; }
         public string BackUrl { get; set; }
         public string ReturnUrl { get; set; }
-        public SigningContextModel SigningContext { get; set; } = new ();
+        public SigningContextModel SigningContext { get; set; } = new();
     }
 }