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/LightningPaymentData.cs

@@ -17,12 +17,12 @@ namespace BTCPayServer.Client.Models
 
         [JsonProperty("BOLT11")]
         public string BOLT11 { get; set; }
-        
+
         public string Preimage { get; set; }
 
         [JsonConverter(typeof(NBitcoin.JsonConverters.DateTimeToUnixTimeConverter))]
         public DateTimeOffset? CreatedAt { get; set; }
-        
+
         [JsonConverter(typeof(LightMoneyJsonConverter))]
         public LightMoney TotalAmount { get; set; }