[CMS] Multisite Manager Dropdown and Search 🔎

We are delighted to introduce an exciting enhancement to our multisite manager, aimed at improving your experience and making the navigation of sites even more convenient.
Key Enhancements ✨
🔎 Search Functionality: Conveniently search for a specific site by typing in keywords. This addition significantly improves the speed and ease of site selection. 
🖥️ User Interface: We have optimized the dropdown menu to display a limited number of connected sites to ensure that you receive a focused and relevant set of results.
💬 User-Friendly Hint Message: To assist you in making the most of the dropdown and search functionality, we have included user-friendly hint messages.