devex: migrate to vue-i18n (#4966)

* sample languages refactor

* feat: consistency + dedupe impl of i18n

* fix: broken imports

* fix: intl formatted component

* fix: use relative imports

* fix: imports

* fix: comment out incomplete locales + fix imports

* feat: cleanup

* fix: ui imports

* fix: lint

* fix: admonition import

* make footer a component, fix language reactivity

* make copyright notice untranslatable

---------

Co-authored-by: Calum H. <contact@cal.engineer>

apps/frontend/src/utils/i18n-project-type.ts

@@ -1,3 +1,5 @@
+import { defineMessages } from '@modrinth/ui'
+
 const projectTypeMessages = defineMessages({
 	datapack: {
 		id: 'project-type.datapack.singular',

apps/frontend/src/utils/muralpay-rails.ts

@@ -1,4 +1,4 @@
-import { defineMessage, type MessageDescriptor } from '@vintl/vintl'
+import { defineMessage, type MessageDescriptor } from '@modrinth/ui'
 
 export type FieldType = 'text' | 'select' | 'email' | 'tel' | 'date'