Add translations to mandatory fields XLSX file

[spwoodcock]

Is your feature request related to a problem? Please describe.

• The mandatory fields XLSX file is used to store useful fields for field data collection.
• This form is merged with a user provided form including the actual survey questions.
• However we do not currently have translations for these questions, only an English version.

Describe the solution you'd like

• We need to add translations for most common languages so that we can merge these with forms where users have included translations.
• The list of all available language codes is ridiculously large: https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
• We should filter down the most useful (initially keep this simple, but then expand out later on):
  • French
  • Spanish
  • Italian
  • Swahili
  • Nepali
  • Hindi
  • Tamil
  • Bengali
  • Chinese simplified (mainland China)
  • Chinese traditional (other)
• If translation fields are included in the user uploaded form, we should match and include the translated columns for the mandatory fields too.

[spwoodcock]

I updated to include Swahili, French, Spanish translations. The others are still pending / some thought for how to solve this.

[spwoodcock]

Update on this:

• For the field: label::spanish(es), the spanish(es) part will be displayed to the user.
  • This label is actually arbitrary, as long as you are consistent with the usage throughout the form: https://forum.getodk.org/t/language-in-the-two-letter-language-list-for-xml/39614/2?
  • pyxform gives us a warning for not using a two letter code, but this is fine 👍
  • The IANA define the language names in English: https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
  • However, for a better user experience, should we consider setting the label in the users language? label::español(es), or perhaps making it title case (capital) label::Español(es).
• Also of note is the usage of the few three letter codes, plus variants, included in the IANA two-letter standard. Examples would be xog for Lusoga or pt-BR for Brazilian Portuguese. We should factor this in.

Also:

• Is this repo any help for the ISO codes / translations? https://github.com/hotosm/iso-countries-languages