Move poll shifts form partial to a component

Thanks to it, we can move a few helper methods to the component.

app/controllers/admin/poll/shifts_controller.rb

@@ -5,8 +5,6 @@ class Admin::Poll::ShiftsController < Admin::Poll::BaseController
   def new
     load_shifts
     @shift = ::Poll::Shift.new
-    @voting_polls = @booth.polls.current
-    @recount_polls = @booth.polls.current_or_recounting
   end
 
   def create