User should be able to change the language of the website

[francisli]

We need to perform localization/internationalization (also known as l10n and i18n) on the codebase so that it can support multiple languages.

We need to research what the best practice tools/libraries/programming conventions are with React to support this in the client single-page app.

We need to update the models so that any user-facing text has additional fields for other languages.