CLASSROOMIO-T-41: Implement dark/light mode switch

Co-authored-by: Rotimi Best <rotimiibitoyeemma@gmail.com>

Merge-request: CLASSROOMIO-MR-8
Merged-by: Digdippa Team <digdippa@gmail.com>

src/components/Snackbar/index.svelte

@@ -56,7 +56,7 @@
         {:else}
           <Information24 class="carbon-icon" />
         {/if}
-        <p class="ml-2 text-lg">{$snackbarStore.message}</p>
+        <p class="dark:text-white ml-2 text-lg">{$snackbarStore.message}</p>
       </div>
 
       <CloseButton onClick={handleClose} contained={true} color="text-white" />