Groups and headings CRUD from budget view

Before, users needed to navigate to the list of groups in order to
add, edit or delete a group.

Also, they need to navigate to the list of groups first, and then to
the list of headings for that group in order to add, edit or delete a
heading.

Now, it's possible to do all these actions for any group or heading
from the participatory budget view to bring simplicity and to reduce
the number of clicks from a user perspective.

Co-Authored-By: Javi Martín <javim@elretirao.net>

app/controllers/concerns/admin/budget_headings_actions.rb

@@ -8,7 +8,6 @@ module Admin::BudgetHeadingsActions
 
     before_action :load_budget
     before_action :load_group
-    before_action :load_headings, only: :index
     before_action :load_heading, only: [:edit, :update, :destroy]
   end
 
@@ -51,10 +50,6 @@ module Admin::BudgetHeadingsActions
       @group = @budget.groups.find_by_slug_or_id! params[:group_id]
     end
 
-    def load_headings
-      @headings = @group.headings.order(:id)
-    end
-
     def load_heading
       @heading = @group.headings.find_by_slug_or_id! params[:id]
     end