Event-based UI translations

[matthijskooijman]

Currently, the entire system has a single language. Currently only English translations are present, but even when e.g. a Dutch translation is added, the user can still select a single language which will change all translated strings.

However, event-specific information (event description, registration fields, etc.) are currently not translated and use the event's native language (there is not much point to use English or English and Dutch field names for a Dutch event), which leads to a mix of languages during the registration procedure. E.g.:

To improve this situation, we could add an event language field, and during the registration procedure, use that language for all translated strings, regardless of the language selected by the user. This will at least lead to a consistent process, and if someone cannot read the registration procedure because of this, they will probably not be the right person to register for the event anyway.

Ideally, only the registration process is translated, not the entire page (i.e. not the menu bar), but I'm not sure if this is feasible. Similarly, ideally each event block in the dashboard and registration history would also use the event's language.