chore: Update inbox view to perform better, added sidebar on inbox views (#12077)

# Pull Request Template

## Description

This PR includes improvements to Inbox view:

1. **Update the route to `:type/:id`**
Previously, we used `notification_id` in the route. This has now been
changed to use a more generic structure like `conversation/:id`, with
`type` set to `"conversation"`. This refactor allows future support for
other types like `contact`, making the route structure more flexible.
It also fixes a critical issue: when a notification is open and a new
notification arrives for the same conversation, the conversation view
used to close unexpectedly. This issue is now resolved.

2. **Migrate components from Options API to Composition API**
Both `InboxList.vue` and `InboxView.vue` have been updated to use the
Composition API with `<script setup>`.

3. **Auto-scroll inbox item into view when navigating**
When navigating through `InboxItemHeader`, the corresponding inbox item
now automatically scrolls into view and load more notifications


## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)


## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/dashboard/components-next/Inbox/InboxCard.vue

@@ -153,7 +153,7 @@ onBeforeMount(contextMenuActions.close);
 <template>
   <div
     role="button"
-    class="flex flex-col w-full gap-2 p-3 transition-all duration-300 ease-in-out cursor-pointer"
+    class="flex flex-col w-full gap-1 p-3 transition-all duration-300 ease-in-out cursor-pointer"
     @contextmenu="contextMenuActions.open($event)"
     @click="emit('click')"
   >
@@ -232,7 +232,7 @@ onBeforeMount(contextMenuActions.close);
             class="flex-shrink-0 text-n-slate-11 size-2.5"
           />
         </div>
-        <span class="text-sm text-n-slate-10">
+        <span class="text-xs text-n-slate-10">
           {{ lastActivityAt }}
         </span>
       </div>