Add translations to new Validate UI

[misaugstad]

Brief description of problem/feature

I haven't added translations to a lot of the text in the new Validate UI. Mostly this is because I'm out of time before heading off to Europe for a vacation! Though it would be nice for us to settle on the text for the new Unsure reason buttons (#3581) and tooltips (#3580), plus some time to iterate on the disagree reason buttons (they were unilaterally decided by me during implementation).

I figure that it's alright, as this UI is just going to be available to Admins for this coming month, but translations will be necessary before rolling out to a larger group of people!