Make reviewing redundant words do something

[max-kamps]

Currently, reviewing redundant words does effectively nothing (since jpdb will just ignore the review). This is confusing and unhelpful. It would be better if the review instead counted towards the non-redundant version of the word.

Unresolved design questions:

• Which non-redundant version should be chosen? The most common one?
  • Unclear how best to handle this... There will need to be several API calls to figure out which word to use
• Should the card state information of the non-redundant version be shown instead? Or maybe the state of both versions?
• Should the alternative spellings be shown to the user?