Update sales' UPRN questions

app/models/form/sales/questions/address_line1.rb

@@ -6,6 +6,7 @@ class Form::Sales::Questions::AddressLine1 < ::Form::Question
     @header = "Address line 1"
     @type = "text"
     @plain_label = true
+    @question_number = 15
   end
 
   def hidden_in_check_answers?(log, _current_user = nil)

app/models/form/sales/questions/uprn.rb

@@ -7,6 +7,7 @@ class Form::Sales::Questions::Uprn < ::Form::Question
     @type = "text"
     @hint_text = "The Unique Property Reference Number (UPRN) is a unique number system created by Ordnance Survey and used by housing providers and sectors UK-wide. For example 10010457355."
     @width = 10
+    @question_number = 14
   end
 
   def unanswered_error_message

spec/models/form/sales/questions/address_line1_spec.rb

@@ -11,6 +11,10 @@ RSpec.describe Form::Sales::Questions::AddressLine1, type: :model do
     expect(question.page).to eq(page)
   end
 
+  it "has the correct question_number" do
+    expect(question.question_number).to eq(15)
+  end
+
   it "has the correct id" do
     expect(question.id).to eq("address_line1")
   end

spec/models/form/sales/questions/uprn_spec.rb

@@ -31,6 +31,10 @@ RSpec.describe Form::Sales::Questions::Uprn, type: :model do
     expect(question.derived?).to be false
   end
 
+  it "has the correct question_number" do
+    expect(question.question_number).to eq(14)
+  end
+
   it "has the correct hint" do
     expect(question.hint_text).to eq("The Unique Property Reference Number (UPRN) is a unique number system created by Ordnance Survey and used by housing providers and sectors UK-wide. For example 10010457355.")
   end