feat: Add new sidebar for Chatwoot V4 (#10291)

This PR has the initial version of the new sidebar targeted for the next major redesign of the app. This PR includes the following changes

- Components in the `layouts-next` and `base-next` directories in `dashboard/components`
- Two generic components `Avatar` and `Icon`
- `SidebarGroup` component to manage expandable sidebar groups with nested navigation items. This includes handling active states, transitions, and permissions.
- `SidebarGroupHeader` component to display the header of each navigation group with optional icons and active state indication.
- `SidebarGroupLeaf` component for individual navigation items within a group, supporting icons and active state.
- `SidebarGroupSeparator` component to visually separate nested navigation items. (They look a lot like header)
- `SidebarGroupEmptyLeaf` component to render empty state of any navigation groups.

----

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

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

@@ -0,0 +1,42 @@
+<script setup>
+import Icon from 'next/icon/Icon.vue';
+
+defineProps({
+  to: { type: [Object, String], default: '' },
+  label: { type: String, default: '' },
+  icon: { type: [String, Object], default: '' },
+  expandable: { type: Boolean, default: false },
+  isExpanded: { type: Boolean, default: false },
+  isActive: { type: Boolean, default: false },
+  hasActiveChild: { type: Boolean, default: false },
+});
+
+const emit = defineEmits(['toggle']);
+</script>
+
+<template>
+  <component
+    :is="to ? 'router-link' : 'div'"
+    class="flex items-center gap-2 px-2 py-1.5 rounded-lg h-8"
+    role="button"
+    :to="to"
+    :title="label"
+    :class="{
+      'text-n-blue bg-n-alpha-2 font-medium': isActive && !hasActiveChild,
+      'text-n-slate-12 font-medium': hasActiveChild,
+      'text-n-slate-11 hover:bg-n-alpha-2': !isActive && !hasActiveChild,
+    }"
+    @click.stop="emit('toggle')"
+  >
+    <Icon v-if="icon" :icon="icon" class="size-4" />
+    <span class="text-sm font-medium leading-5 flex-grow">
+      {{ label }}
+    </span>
+    <span
+      v-if="expandable"
+      v-show="isExpanded"
+      class="i-lucide-chevron-up size-3"
+      @click.stop="emit('toggle')"
+    />
+  </component>
+</template>