Use bulk indexer for projects

config/gitlab.yml.example

config/initializers/1_settings.rb

config/sidekiq_queues.yml

ee/app/models/concerns/elastic/projects_search.rb

ee/app/models/elasticsearch_indexed_project.rb

ee/app/services/elastic/index_projects_by_id_service.rb

ee/app/services/elastic/index_record_service.rb

ee/app/services/elastic/process_bookkeeping_service.rb

...p/services/elastic/process_initial_bookkeeping_service.rb

ee/app/workers/all_queues.yml

ee/app/workers/concerns/elastic/bulk_cron_worker.rb

ee/app/workers/concerns/elastic/indexing_control.rb

ee/app/workers/elastic_delete_project_worker.rb

ee/app/workers/elastic_full_index_worker.rb

ee/app/workers/elastic_index_bulk_cron_worker.rb

ee/app/workers/elastic_index_initial_bulk_cron_worker.rb

ee/app/workers/elastic_indexer_worker.rb

ee/app/workers/elastic_namespace_indexer_worker.rb

ee/lib/elastic/metrics_update_service.rb

ee/lib/tasks/gitlab/elastic.rake