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/provider.js

@@ -0,0 +1,49 @@
+import { inject, provide } from 'vue';
+import { usePolicy } from 'dashboard/composables/usePolicy';
+import { useRouter } from 'vue-router';
+
+const SidebarControl = Symbol('SidebarControl');
+
+export function useSidebarContext() {
+  const context = inject(SidebarControl, null);
+  if (context === null) {
+    throw new Error(`Component is missing a parent <Sidebar /> component.`);
+  }
+
+  const router = useRouter();
+  const { checkFeatureAllowed, checkPermissions } = usePolicy();
+
+  const resolvePath = to => {
+    if (to) return router.resolve(to)?.path || '/';
+    return '/';
+  };
+
+  const resolvePermissions = to => {
+    if (to) return router.resolve(to)?.meta?.permissions ?? [];
+    return [];
+  };
+
+  const resolveFeatureFlag = to => {
+    if (to) return router.resolve(to)?.meta?.featureFlag || '';
+    return '';
+  };
+
+  const isAllowed = to => {
+    const permissions = resolvePermissions(to);
+    const featureFlag = resolveFeatureFlag(to);
+
+    return checkPermissions(permissions) && checkFeatureAllowed(featureFlag);
+  };
+
+  return {
+    ...context,
+    resolvePath,
+    resolvePermissions,
+    resolveFeatureFlag,
+    isAllowed,
+  };
+}
+
+export function provideSidebarContext(context) {
+  provide(SidebarControl, context);
+}