AO3-6868 Add language form validation #4832

Job	Run time
rake db:otwseed	2m 12s
rspec spec/controllers	13m 13s
rspec spec/models	5m 59s
rspec --exclude-pattern 'spec/{controllers,models}/*/.rb'	8m 28s
cucumber features/admins	6m 42s
cucumber features/bookmarks	6m 12s
cucumber features/collections	6m 0s
cucumber features/comments_and_kudos	6m 54s
cucumber features/gift_exchanges	6m 51s
cucumber features/importing	2m 52s
cucumber features/other_a	11m 26s
cucumber features/other_b	6m 24s
cucumber features/prompt_memes_a	4m 34s
cucumber features/prompt_memes_b	3m 45s
cucumber features/prompt_memes_c	4m 52s
cucumber features/search	6m 39s
cucumber features/tag_sets	3m 17s
cucumber features/tags_and_wrangling	7m 15s
cucumber features/users	6m 12s
cucumber features/works	13m 8s
	2h 12m 55s

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