[#4289] Ported the billing plugin's timesheet hooks.

init.rb

@@ -31,7 +31,9 @@ Redmine::Plugin.register :redmine_rate do
   permission :view_rate, { }
 end
 
+require 'redmine_rate/hooks/timesheet_hook_helper'
 require 'redmine_rate/hooks/plugin_timesheet_views_timesheets_time_entry_row_class_hook'
 require 'redmine_rate/hooks/plugin_timesheet_views_timesheet_group_header_hook'
 require 'redmine_rate/hooks/plugin_timesheet_views_timesheet_time_entry_hook'
 require 'redmine_rate/hooks/plugin_timesheet_views_timesheet_time_entry_sum_hook'
+require 'redmine_rate/hooks/plugin_timesheet_view_timesheets_report_header_tags_hook'