feat(dossier): fork dossier when editing en construction

app/views/shared/dossiers/_edit.html.haml

@@ -1,17 +1,13 @@
+- dossier_for_editing = dossier.en_construction? ? dossier.owner_editing_fork : dossier
+
 - if dossier.france_connect_information.present?
   - content_for(:notice_info) do
     = render partial: "shared/dossiers/france_connect_informations_notice", locals: { user_information: dossier.france_connect_information }
 
 .dossier-edit.container.counter-start-header-section
   = render partial: "shared/dossiers/submit_is_over", locals: { dossier: dossier }
-
-  - if dossier.brouillon?
-    - form_options = { url: brouillon_dossier_url(dossier), method: :patch }
-  - else
-    - form_options = { url: modifier_dossier_url(dossier), method: :patch }
   = render NestedForms::FormOwnerComponent.new
-  = form_for dossier, form_options.merge({ html: { id: 'dossier-edit-form', class: 'form', multipart: true, novalidate: 'novalidate' } }) do |f|
-
+  = form_for dossier_for_editing, url: brouillon_dossier_url(dossier), method: :patch, html: { id: 'dossier-edit-form', class: 'form', multipart: true, novalidate: 'novalidate' } do |f|
     %header.mb-6
       .fr-highlight
         %p.fr-text--sm
@@ -42,5 +38,7 @@
         = f.select :groupe_instructeur_id,
           dossier.procedure.groupe_instructeurs.active.map { |gi| [gi.label, gi.id] },
           { include_blank: dossier.brouillon? }
-    = render EditableChamp::SectionComponent.new(champs: dossier.champs_public)
-  = render Dossiers::EditFooterComponent.new(dossier: dossier, annotation: false)
+
+
+    = render EditableChamp::SectionComponent.new(champs: dossier_for_editing.champs_public)
+  = render Dossiers::EditFooterComponent.new(dossier: dossier_for_editing, annotation: false)