Navigation structure improvements

The left-hand navigation has been redesigned to improve usability and orientation within the Climate Hub.

• The menu items Reports and Standards have been moved under the new main section CO₂ Accounting.
• This new structure groups related functionalities together and creates a clearer, more intuitive navigation experience.
• Breadcrumbs have been introduced at the top of the page for the Company and Accounting sections, allowing users to easily understand their current location within the application and navigate back to higher-level sections.