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/ViewPullPaymentModel.cs

@@ -91,7 +91,7 @@ namespace BTCPayServer.Models
         public string Description { get; set; }
         public string EmbeddedCSS { get; set; }
         public string CustomCSSLink { get; set; }
-        public List<PayoutLine> Payouts { get; set; } = new ();
+        public List<PayoutLine> Payouts { get; set; } = new();
         public DateTimeOffset StartDate { get; set; }
         public DateTime LastRefreshed { get; set; }
         public CurrencyData CurrencyData { get; set; }