fix z-index on sticky footer and fix breadcrumb putting back .sub-header class

app/assets/stylesheets/forms.scss

@@ -649,4 +649,5 @@ textarea::placeholder {
   bottom: 0;
   padding: $default-padding 0;
   background-color: $white;
+  z-index: 2;
 }

app/views/administrateurs/_breadcrumbs.html.haml

@@ -1,4 +1,4 @@
-#breadcrumbs
+#breadcrumbs.sub-header
   .fr-container.flex.justify-between.align-baseline.column
     %nav.fr-breadcrumb.mt-0{ role: "navigation", aria: { label: t('you_are_here', scope: [:layouts, :breadcrumb]) } }
       %button.fr-breadcrumb__button{ aria: { expanded: "false", controls: "breadcrumb-1" } }

app/views/administrateurs/procedures/show.html.haml

@@ -1,10 +1,9 @@
-.sub-header
-  = render partial: 'administrateurs/breadcrumbs',
+= render partial: 'administrateurs/breadcrumbs',
     locals: { steps: [['Démarches', admin_procedures_back_path(@procedure)],
                       ["#{@procedure.libelle.truncate_words(10)}"]],
               metadatas: true }
 
-  .fr-container.procedure-admin-container
+.fr-container.procedure-admin-container
   %ul.fr-btns-group.fr-btns-group--inline-sm.fr-btns-group--icon-left
     - if @procedure.draft_revision.valid?
       - if !@procedure.brouillon?