feat: Add unread badge to sidebar for inbox view (#10803)

# Pull Request Template

## Description

This PR adds a badge to the icon in the sidebar group header and an
unread highlight for the inbox view.

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

**Loom video**

https://www.loom.com/share/1a880aa16de249a1836b8d014325c067?sid=87cc7b64-667b-4066-8993-d33abccf7b67


## 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

app/javascript/dashboard/components-next/sidebar/SidebarGroup.vue

@@ -15,6 +15,7 @@ const props = defineProps({
   to: { type: Object, default: null },
   activeOn: { type: Array, default: () => [] },
   children: { type: Array, default: undefined },
+  getterKeys: { type: Object, default: () => ({}) },
 });
 
 const {
@@ -143,6 +144,7 @@ onMounted(async () => {
       :name
       :label
       :to
+      :getter-keys="getterKeys"
       :is-active="isActive"
       :has-active-child="hasActiveChild"
       :expandable="hasChildren"