Changelly Support (#267)

* 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

BTCPayServer/Models/StoreViewModels/StoreViewModel.cs

@@ -21,7 +21,13 @@ namespace BTCPayServer.Models.StoreViewModels
             public WalletId WalletId { get; set; }
             public bool Enabled { get; set; }
         }
-
+        
+        public class ThirdPartyPaymentMethod
+        {
+            public string Provider { get; set; }
+            public bool Enabled { get; set; }
+            public string Action { get; set; }
+        }
         public StoreViewModel()
         {
 
@@ -52,6 +58,9 @@ namespace BTCPayServer.Models.StoreViewModels
 
         public List<StoreViewModel.DerivationScheme> DerivationSchemes { get; set; } = new List<StoreViewModel.DerivationScheme>();
 
+        public List<ThirdPartyPaymentMethod> ThirdPartyPaymentMethods { get; set; } =
+            new List<ThirdPartyPaymentMethod>();
+
         [Display(Name = "Invoice expires if the full amount has not been paid after ... minutes")]
         [Range(1, 60 * 24 * 24)]
         public int InvoiceExpiration