ForgeVTT module translations

[rikmarais]

• Request a weblate project in weblate.foundryvtt-hub.com to treat it like a proper Foundry module and bundle i18n strings with the release.
• Rework the way interpolation happens to use proper Foundry interpolation where we need to use it to introduce the game slug into strings and such, even in cases where this happens before Foundry translations have properly been initialized. This can likely be done by marking the module as a coreLanguage module in the init step in the Forge module itself.