Multiple entries: Allow specifying language for the original name and support translations to other languages

[riipah]

Currently titles can only be translated to 4 "content language selection" presets: Non-English, Romanized, English and Undefined (used for aliases). There's demand to support translations into other languages as well, for example German and Russian, or a Japanese title could be translated into Chinese.

First step is to allow specifying the exact language for the "non-English" name. This could be done similar to lyrics: there's fixed fields for original name and Romanization, plus variable number of fields for translations. For entry titles, aliases should be kept separate from translations of the primary name.

I think it's best to start with mapping those new language options to the current content language selection. This would still allow only English translation to be sorted and displayed in listings, but it'd be an improvement compared to current state, and would prepare the way for further improvements.

• Edit view: change current primary name editor to similar to lyrics. Original name, Romanized name, translations. Language can be selected (from dropdown) for original name and translations. Language options are identical to lyrics, including other/unknown.
  • Editing for aliases will remain as it is.
• Song page: all translations and aliases, including original and Romanized will be shown. First name to be shown is chosen like it's done now.
• Translations other than English will be treated like aliases for now. They cannot be used for sorting or as display name.

TODO: is there need to specify translations for aliases? This could be used to hide/show translations of aliases based on user's language setting. It would also enable varying artist name (with translations) per album/song (see VocaDB/community#68).