Enhance CSV button

...xtures/RepresentativeListTest.test_filter_chamber.content

...xtures/RepresentativeListTest.test_filter_country.content

...fixtures/RepresentativeListTest.test_filter_group.content

...tures/RepresentativeListTest.test_filter_multiple.content

...tures/RepresentativeListTest.test_filter_notfound.content

...ixtures/RepresentativeListTest.test_filter_search.content

...stTest.test_page1_paginateby12_active_displaylist.content

...eListTest.test_page1_paginateby12_all_displaylist.content

...st.test_page1_paginateby12_displaylist_searchjoly.content

...stTest.test_page1_paginateby24_active_displaygrid.content

...eListTest.test_page1_paginateby24_all_displaygrid.content

...ativeListTest.test_page2_paginateby12_displaylist.content

...ativeListTest.test_page2_paginateby24_displaylist.content

templates/representatives/_filter_form.haml