AO3-6565 Move admin user search to Elasticsearch, add past emails and username search #4956

Job	Run time
rake db:otwseed	1m 12s
rspec spec/controllers	14m 8s
rspec spec/models	5m 56s
rspec --exclude-pattern 'spec/{controllers,models}/*/.rb'	8m 19s
cucumber features/admins	7m 46s
cucumber features/bookmarks	5m 41s
cucumber features/collections	6m 58s
cucumber features/comments_and_kudos	9m 41s
cucumber features/gift_exchanges	7m 24s
cucumber features/importing	2m 44s
cucumber features/other_a	11m 55s
cucumber features/other_b	7m 8s
cucumber features/prompt_memes_a	4m 6s
cucumber features/prompt_memes_b	3m 58s
cucumber features/prompt_memes_c	4m 54s
cucumber features/search	7m 39s
cucumber features/tag_sets	4m 40s
cucumber features/tags_and_wrangling	8m 19s
cucumber features/users	5m 25s
cucumber features/works	13m 0s
	2h 20m 53s

Provide feedback