Add support for multi-lingual interface

[janbur]

Problem

GeoSight is used by users in many different countries. Currently, the User Interface is only available in English language. We need to enable the multi-lingual interface, both in the front-end as well as in the admin interface.

Solution

Add multilingual support to both Django and React components.

• enable and configure the Django built-in support for internationalization (i18n) and localization (l10n) as well as in React
• in the code and templates (both for the admin UI as well as dashboard / frontend UI) mark all the strings for translation so they can be translated using Django’s built-in translation tools
• generate translation files ".po" (Portable Object) files that contain the text to be translated
• translate strings
• compile the .po files into .mo (Machine Object) files that Django uses at runtime
• other configurations as needed (e.g. middleware configuration etc)
• add a Language Switcher to provide a way for users to change their language preference
• ensure that URLs are configured to support multi-lingual UI
• ensure that media and static files can also support multi-lingual UI
• write unit tests and E2E test
• document the new functionality (both for developers and users)

Sample implementation of the Language Switcher in the Dashboard interface:

Sample implementation of the Language Switcher in the Admin interface: