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>

packages/ui/src/components/affiliate/AffiliateLinkCard.vue

@@ -33,9 +33,9 @@
 <script setup lang="ts">
 import { AffiliateIcon, XCircleIcon } from '@modrinth/assets'
 import type { AffiliateLink } from '@modrinth/utils'
-import { defineMessages, useVIntl } from '@vintl/vintl'
 
-import { AutoBrandIcon, ButtonStyled, CopyCode } from '../index.ts'
+import { defineMessages, useVIntl } from '../../composables/i18n'
+import { AutoBrandIcon, ButtonStyled, CopyCode } from '../index'
 
 withDefaults(
 	defineProps<{

packages/ui/src/components/affiliate/AffiliateLinkCreateModal.vue

@@ -64,10 +64,10 @@
 <script lang="ts"></script>
 <script setup lang="ts">
 import { AffiliateIcon, PlusIcon, SpinnerIcon, UserIcon, XIcon } from '@modrinth/assets'
-import { defineMessages, useVIntl } from '@vintl/vintl'
 import { computed, ref, useTemplateRef } from 'vue'
 
-import { AutoBrandIcon, Button, ButtonStyled, NewModal } from '../index.ts'
+import { defineMessages, useVIntl } from '../../composables/i18n'
+import { AutoBrandIcon, Button, ButtonStyled, NewModal } from '../index'
 export type CreateAffiliateProps = { sourceName: string; username?: string }
 
 const props = withDefaults(