feat: multi language support (#254)

* feat: multitranslational support

* - completion of settings page
- completion of sidebar

* sidebar rerendering bug fix

* completion of the lesson navigation & materials page

* completion of the course navigation

* completion of requested languages

* - Implementation of Language Picker
- Rename Bug Fixes

* checkpoint save

* - addition of the language picker to the onboarding.
- addition of the language switcher for the lesson notes.

* merge completion

* initialization of the new branch

* add transition.svelte file

* lesson note bug fix

* feat: add translation migration

* completion of translation

* fix height issue of dropdown

* refactoring

* fix: improve code with LOCALE from db

* finally get it fully functional

* connect with AI

* backward compatibility for lesson note

* preserve old content, when generating AI content

* undo translations in upgrade modal

* fix duplicate key issue from codacy trigger

---------

Co-authored-by: Rotimi Best <best@classroomio.com>

apps/dashboard/src/lib/components/Form/TextArea.svelte

@@ -1,10 +1,11 @@
 <script lang="ts">
   import CustomPromptBtn from '$lib/components/AI/AIButton/CustomPromptBtn.svelte';
   import type { PopoverProps } from 'carbon-components-svelte/types/Popover/Popover.svelte';
+  import { t } from '$lib/utils/functions/translations';
 
   export let label = '';
   export let disabled = false;
-  export let placeholder = 'Write your answer...';
+  export let placeholder = $t('course.navItem.lessons.exercises.all_exercises.write_your_answer');
   export let value = '';
   export let rows = 3;
   // export let maxRows = 3;