fix: remove useSidebar to fix errors of SidebarWrapper when opening playground page

[lucaseduoli]

This pull request includes several changes to improve the handling of the sidebar state in the frontend codebase. The main changes involve removing the useSidebar hook and replacing it with data attributes to manage the sidebar's open state.

Sidebar state management improvements:

• src/frontend/src/components/ui/sidebar.tsx: Added a data-open attribute to manage the sidebar's open state.
• src/frontend/src/pages/FlowPage/components/PageComponent/index.tsx: Removed the useSidebar hook and replaced it with data attributes in various components to handle the sidebar's open state. [1] [2] [3] [4]

Code cleanup:

• src/frontend/src/pages/MainPage/components/header/index.tsx: Removed the useSidebar hook and updated the class names to use data attributes for managing the sidebar's open state. [1] [2] [3]