style(instructeurs): convert some dropdowns buttons to DSFR

app/components/dossiers/export_component/export_component.html.haml

@@ -1,5 +1,5 @@
 %span.dropdown{ data: { controller: 'menu-button' } }
-  %button.button.dropdown-button{ data: { menu_button_target: 'button' } }
+  %button.fr-btn.fr-btn--secondary.fr-btn--sm.dropdown-button{ data: { menu_button_target: 'button' } }
     - if @count.nil?
       = t(".download_all")
     - else

app/components/dossiers/filter_component/filter_component.html.haml

@@ -9,5 +9,4 @@
     %input#value{ type: field_type, name: :value, maxlength: ProcedurePresentation::FILTERS_VALUE_MAX_LENGTH, disabled: field_id.nil? ? true : false }
 
   = hidden_field_tag :statut, statut
-  %br
-  = submit_tag t('.add_filter'), class: 'button'
+  = submit_tag t('.add_filter'), class: 'fr-btn fr-btn--secondary fr-mt-2w'

app/views/instructeurs/procedures/_dossiers_filter.html.haml

@@ -1,5 +1,5 @@
 %span.dropdown{ data: { controller: 'menu-button', popover: 'true' } }
-  %button.button.dropdown-button{ data: { menu_button_target: 'button' } }
+  %button.fr-btn.fr-btn--secondary.fr-btn--sm.fr-mr-1w.dropdown-button{ data: { menu_button_target: 'button' } }
     = t('views.instructeurs.dossiers.filters.title')
   #filter-menu.dropdown-content.left-aligned.fade-in-down{ data: { menu_button_target: 'menu' } }
     = render Dossiers::FilterComponent.new(procedure: procedure, procedure_presentation: @procedure_presentation, statut: statut)

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

@@ -94,7 +94,7 @@
 
                 %th.action-col.follow-col
                   %span.dropdown{ data: { controller: 'menu-button', popover: 'true' } }
-                    %button.button.dropdown-button{ data: { menu_button_target: 'button' } }
+                    %button.fr-btn.fr-btn--sm.fr-btn--secondary.dropdown-button{ data: { menu_button_target: 'button' } }
                       = t('views.instructeurs.dossiers.personalize')
                     #custom-menu.dropdown-content.fade-in-down{ data: { menu_button_target: 'menu' } }
                       = form_tag update_displayed_fields_instructeur_procedure_path(@procedure), method: :patch, class: 'dropdown-form large columns-form' do