build: switch from yarn to npm to manage js dependencies and move js contents to root

yarn v1 is being deprecated and starts to have some issues

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

src/plugins/dateFns.ts

@@ -0,0 +1,22 @@
+import type { Locale } from "date-fns";
+import { App } from "vue";
+
+export const dateFnsPlugin = {
+  install(app: App, options: { locale: string }) {
+    function dateFnsfileForLanguage(lang: string) {
+      const matches: Record<string, string> = {
+        en: "en-US",
+      };
+      return matches[lang] ?? lang.replace("_", "-");
+    }
+
+    import(
+      `../../node_modules/date-fns/esm/locale/${dateFnsfileForLanguage(
+        options.locale
+      )}/index.js`
+    ).then((localeEntity: { default: Locale }) => {
+      app.provide("dateFnsLocale", localeEntity.default);
+      app.config.globalProperties.$dateFnsLocale = localeEntity.default;
+    });
+  },
+};