loading-screen: Make translations regionless

This allows matching a much wider set of locales without depending on
the browser to build `navigator.languages` as we expect it. Furthermore,
we're not actually providing regional translation variation and probably
never will.

Fixes: #893

Author: dbnicholson

packages/loading-screen/lang/en-US.json renamed to packages/loading-screen/lang/en.json

@@ -7,7 +7,7 @@
     "build": "yarn run compile-messages && vue-cli-service build --no-module && yarn zip",
     "lint": "vue-cli-service lint",
     "zip": "../../scripts/bundle_zip.py loading-screen.zip",
-    "extract-messages": "formatjs extract 'src/**/*.{js,vue}' --format transifex --out-file lang/en-US.json",
+    "extract-messages": "formatjs extract 'src/**/*.{js,vue}' --format transifex --out-file lang/en.json",
     "compile-messages": "formatjs compile-folder --format transifex lang compiled-lang"
   },
   "dependencies": {

packages/loading-screen/lang/es-419.json renamed to packages/loading-screen/lang/es.json

@@ -11,8 +11,8 @@ import LoadingRetry from '@/views/LoadingRetry.vue';
 import store from "@/store";
 
 // Language codes are RFC 5646 (https://datatracker.ietf.org/doc/html/rfc5646)
-const supportedLocales = ['en-US', 'es-419'];
-const defaultLocale = 'en-US';
+const supportedLocales = ['en', 'es'];
+const defaultLocale = 'en';
 const requestedLocales = navigator.languages;
 
 function loadLocaleData(locale) {