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/Forms/FormDataService.cs

@@ -15,7 +15,7 @@ public class FormDataService
 
     public static readonly Form StaticFormEmail = new()
     {
-        Fields = new List<Field>() {Field.Create("Enter your email", "buyerEmail", null, true, null, "email")}
+        Fields = new List<Field>() { Field.Create("Enter your email", "buyerEmail", null, true, null, "email") }
     };
 
     public static readonly Form StaticFormAddress = new()