Review and consolidate the design of VF mega menu

[nikiforosk]

The design of VF mega menu in Figma is different from the vf mega menu component in HTML and the implementation of vf mega menu in the VF site.

We want to:

• [ ] Review these three versions
• [ ] Propose an updated design in Figma that incorporates their strengths
• [ ] In the proposal consider the IA of the EMBL-EBI Intranet as the main application context of the updated design
• [ ] Update the documentation for the revised design

Designs to review:

• [ ] VF mega menu in Figma
• [ ] vf mega menu component in HTML
• [ ] implementation of vf mega menu in the VF site

Previous discussions about the megamenu and related links are in #1794

[nikiforosk]

@Adedoyinebi currently working on the megamenu version for the Intranet. Will review this task once the Intranet work is done, including a responsive variant for smaller screens.