AO3-6868 Add language form validation #4836

Job	Run time
rake db:otwseed	2m 10s
rspec spec/controllers	12m 34s
rspec spec/models	5m 59s
rspec --exclude-pattern 'spec/{controllers,models}/*/.rb'	8m 10s
cucumber features/admins	8m 9s
cucumber features/bookmarks	4m 48s
cucumber features/collections	6m 36s
cucumber features/comments_and_kudos	7m 7s
cucumber features/gift_exchanges	7m 12s
cucumber features/importing	2m 53s
cucumber features/other_a	10m 25s
cucumber features/other_b	7m 9s
cucumber features/prompt_memes_a	3m 59s
cucumber features/prompt_memes_b	3m 45s
cucumber features/prompt_memes_c	5m 18s
cucumber features/search	6m 24s
cucumber features/tag_sets	3m 12s
cucumber features/tags_and_wrangling	8m 24s
cucumber features/users	4m 50s
cucumber features/works	13m 44s
	2h 12m 48s

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