Add toggle to hide review accuracy

[matchai]

Hey Tsurukame maintainers 👋

I'd love to see a simple toggle in the settings to hide the review accuracy % during reviews, much like the Hide Review Accuracy user script does.

It's a small change, but starting a review session with a few blunders drops the accuracy score and seeing my low accuracy discourages me. Installing the user script boosted my mood when reviewing – I'd love to see it added to the app. 😊

[matchai]

It seems this may have been addressed by #231, but I can't seem to find the option in Settings. I'd expect to find it in Settings > Reviews > Display > Hide Review Accuracy, but it doesn't seem to be there.

[UInt2048]

#231 was only for lessons not reviews.