Respect current controller scope when using search from project area

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/layouts/_search.html.haml

@@ -4,7 +4,16 @@
     = hidden_field_tag :group_id, @group.try(:id)
     - if @project && @project.persisted?
       = hidden_field_tag :project_id, @project.id
+
+      - if current_controller?(:issues)
+        = hidden_field_tag :scope, 'issues'
+      - elsif current_controller?(:merge_requests)
+        = hidden_field_tag :scope, 'merge_requests'
+      - elsif current_controller?(:wikis)
+        = hidden_field_tag :scope, 'wiki_blobs'
+      - else
         = hidden_field_tag :search_code, true
+
     - if @snippet || @snippets
       = hidden_field_tag :snippets, true
     = hidden_field_tag :repository_ref, @ref

app/views/search/_project_filter.html.haml

@@ -25,6 +25,7 @@
         = @search_results.notes_count
   %li{class: ("active" if @scope == 'wiki_blobs')}
     = link_to search_filter_path(scope: 'wiki_blobs') do
+      %i.fa.fa-book
       Wiki
       .pull-right
         = @search_results.wiki_blobs_count