Make Invoice Create Faster And Fix Gap Limit Issue (#1843)

* Make Invoice Create Faster And Fix Gap Limit Issue

This make address reserve only when user "activate" paymet method in ui. optional setting in store checkout ui.

* Fix swagger documentation around Lazy payment methods

* fix changed code signature

* Add missing GreenField API for activate feature

* Fix checkout experience styling for activate feature

* Fix issue with Checkout activate button

* Make lightning also work with activation

* Make sure PreparePaymentModel is still called on payment handlers even when unactivated

* Make payment  link return empty if not activated

* Add activate payment method method to client and add test

* remove debugger

* add e2e test

* Rearranging lazy payments position in UI to be near dependent Unified QR code

* fix rebase conflicts

* Make lazy payment method mode activate on UI load.

Co-authored-by: Kukks <evilkukka@gmail.com>
Co-authored-by: rockstardev <rockstardev@users.noreply.github.com>
Co-authored-by: Andrew Camilleri <kukks@btcpayserver.org>

BTCPayServer/Models/StoreViewModels/CheckoutExperienceViewModel.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
-using BTCPayServer.Data;
 using BTCPayServer.Payments;
 using BTCPayServer.Services;
 using Microsoft.AspNetCore.Mvc.Rendering;
@@ -45,6 +44,9 @@ namespace BTCPayServer.Models.StoreViewModels
         [Display(Name = "Include lightning invoice fallback to on-chain BIP21 payment url")]
         public bool OnChainWithLnInvoiceFallback { get; set; }
 
+        [Display(Name = "Only enable the payment method after user explicitly chooses it")]
+        public bool LazyPaymentMethods { get; set; }
+
         [Display(Name = "Redirect invoice to redirect url automatically after paid")]
         public bool RedirectAutomatically { get; set; }