form: extract the form header to its own partial

app/assets/stylesheets/new_design/dossier-edit.scss

@@ -1,13 +1,9 @@
 @import "colors";
 @import "constants";
 
-.dossier-edit {
-  .dossier-header {
-    background-color: $light-grey;
-    margin-bottom: $default-padding;
-
+.dossier-header {
   .container {
-      padding: $default-padding;
+    padding-bottom: $default-padding;
   }
 
   h1 {
@@ -17,8 +13,15 @@
       vertical-align: -3px;
     }
   }
-  }
 
+  .dossier-form-actions {
+    margin-top: $default-padding;
+    margin-bottom: $default-padding;
+    text-align: right;
+  }
+}
+
+.dossier-edit {
   .prologue {
     margin: (1.5 * $default-padding) 0;
     display: flex;

app/views/new_user/dossiers/modifier.html.haml

@@ -2,10 +2,8 @@
   = render partial: "new_user/dossiers/footer", locals: { dossier: @dossier }
 
 .dossier-edit
-  .dossier-header
+  .dossier-header.sub-header
     .container
-      %h1
-        %span.icon.folder
-        = @dossier.procedure.libelle
+      = render partial: "shared/dossiers/header", locals: { dossier: @dossier, apercu: false }
 
   = render partial: "shared/dossiers/edit", locals: { dossier: @dossier, apercu: false }

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

@@ -0,0 +1,3 @@
+%h1
+  %span.icon.folder
+  = dossier.procedure.libelle