remove legacy code

app/models/invoice.rb

@@ -40,11 +40,6 @@ class Invoice < ApplicationRecord
 
   attribute :vat_rate, ::Type::VatRate.new
 
-  def get_status_from_billing
-    response = EisBilling::GetInvoiceStatus.send_invoice(invoice_number: number)
-    JSON.parse(response.body, symbolize_names: true)[:status]
-  end
-
   def set_invoice_number
     if Feature.billing_system_integrated?
       result = EisBilling::GetInvoiceNumber.send_invoice

app/presenters/registrar/invoice_status_presenter.rb

@@ -1,18 +0,0 @@
-class Registrar::InvoiceStatusPresenter
-  include ActionView::Helpers::TagHelper
-
-  attr_reader :invoice
-
-  def initialize(invoice:)
-    @invoice = invoice
-  end
-
-  def display
-    case invoice.get_status_from_billing
-    when 'unpaid'
-      content_tag(:span, 'Unpaid', style: 'color: red;')
-    when 'paid'
-      content_tag(:span, 'Unpaid', style: 'color: red;')
-    end
-  end
-end

app/services/eis_billing/get_invoice_status.rb

@@ -1,18 +0,0 @@
-module EisBilling
-  class GetInvoiceStatus < EisBilling::Base
-    def self.send_invoice(invoice_number:)
-      send_request(invoice_number: invoice_number)
-    end
-
-    private
-
-    def self.send_request(invoice_number:)
-      http = EisBilling::Base.base_request(url: invoice_number_generator_url)
-      http.get(invoice_number_generator_url + "/#{invoice_number}", EisBilling::Base.headers)
-    end
-
-    def self.invoice_number_generator_url
-      "#{BASE_URL}/api/v1/invoice_generator/invoice_status"
-    end
-  end
-end

app/views/registrar/invoices/partials/_details.haml

@@ -34,7 +34,3 @@
 
   %dt= Invoice.human_attribute_name :reference_no
   %dd= @invoice.reference_no
-
-  - invoice_presenter = Registrar::InvoiceStatusPresenter.new(invoice: @invoice)
-  %dt Billing system
-  %dd= invoice_presenter.display