Overhaul localization and accept croudsourced translations

[noahm]

Currently a lot of the UI has some hand-coded alternate strings for Ukranian language, but they're all disabled at the moment. Given the newfound international popularity of Clearsky, I think we should enable localization for all languages, and even better, the international community can easily help contribute translations with the use of a translation management platform!

Many platforms out there offer free plans for open source projects like Clearsky. Several that I'm at least a little familiar with:

• Crowdin - commercial, free to open source projects
• Locize - commercia, free to open source projects
• Weblate - Open source, Self-hostable and hosted (maybe free to Libre projects? their docs aren't clear to me)
• Pontoon - Used for Firefox's localization, Open source, self-hostable

Setting all this up will ultimately involve two steps:

• replacing all the custom localise function calls within the app with something more standard like react-intl that supports string extraction and loading in locales from external sources
• setting up an account with one of the above providers and integrating the repo with it