Navigation Block: Merge open and close buttons into a single toggle button

[huubl]

What problem does this address?

The current implementation of the navigation block includes separate buttons for opening and closing the menu. This design makes it challenging to apply animations or transitions between the open and close states (like this).

What is your proposed solution?

To enhance the flexibility and usability of the navigation block, I propose merging the open and close buttons into a single toggle button. This button's state, icon, and aria-label can dynamically change based on the menu's current state (open or closed).