Changelly v2 (#343)

* Disable shapeshift and use changelly

* UI to manage changelly payment method

* wip on changelly api

* Add in Vue component for changelly and remove target currency from payment method

* add changelly merhcant id

* Small fixes to get Conversion to load

* wip fixing the component

* fix merge conflict

* fixes to UI

* remove debug, fix fee calc and move changelly to own partials

* Update ChangellyController.cs

* move original vue setup back to checkout

* Update core.js

* Extracting Changelly component to js file

* Proposal for loading spinner

* remove zone

* imrpove changelly ui

* add in changelly config checks

* try new method to calculate amount + remove to currency from list

* abstract changelly lofgic to provider and reduce dependency on js component

* Add UTs for Changelly

* refactor changelly backend

* fix failing UT

* add shitcoin tax

* pr changes

* pr changes

* WIP: getting rid of changelly dependency

* client caching, compiling code, cleaner code

* Cleaner changelly

* fiat!

* updat i18n, css and error styler

* default keys

* pr changes part 1

* part2

* fix tests

* fix loader alignment and retry button responsiveness

* final pr change

BTCPayServer/Models/StoreViewModels/UpdateChangellySettingsViewModel.cs

@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.InteropServices;
+using BTCPayServer.Payments;
+using Microsoft.AspNetCore.Mvc.Rendering;
+
+namespace BTCPayServer.Models.StoreViewModels
+{
+    public class UpdateChangellySettingsViewModel
+    {
+        [Required] public string ApiKey { get; set; } = "6ed02cdf1b614d89a8c0ceb170eebb61";
+
+        [Required] public string ApiSecret { get; set; } = "8fbd66a2af5fd15a6b5f8ed0159c5842e32a18538521ffa145bd6c9e124d3483";
+
+        [Required] public string ApiUrl { get; set; } = "https://api.changelly.com";
+
+        [Display(Name = "Optional, Changelly Merchant Id")]
+        public string ChangellyMerchantId { get; set; } = "804298eb5753";
+
+        [Display(Name = "Show Fiat Currencies as option in conversion")]
+        public bool ShowFiat { get; set; } = true;
+
+        [Required]
+        [Range(0, 100)]
+        [Display(Name =
+            "Percentage to multiply amount requested at Changelly to avoid underpaid situations due to Changelly not guaranteeing rates. ")]
+        public decimal AmountMarkupPercentage { get; set; } = new decimal(2);
+
+        public bool Enabled { get; set; } = true;
+
+        public string StatusMessage { get; set; }
+    }
+}