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.Client/Models/CreateLightningInvoiceRequest.cs

@@ -11,14 +11,14 @@ namespace BTCPayServer.Client.Models
         {
 
         }
-        
+
         public CreateLightningInvoiceRequest(LightMoney amount, string description, TimeSpan expiry)
         {
             Amount = amount;
             Description = description;
             Expiry = expiry;
         }
-        
+
         [JsonConverter(typeof(JsonConverters.LightMoneyJsonConverter))]
         public LightMoney Amount { get; set; }
         public string Description { get; set; }