[ic-footer] Retro-fit ic-accordion-group

[gd2910]

Summary

ic-footer with grouped links currently has a custom accordion like design pattern. Retrofitting to use an ic-accordion-group would give developers more control over the grouped links and bring more a11y to the component (ie, focus states, animation.

💬 Description

Ticket will have to go through Design to have ic-accordion work on a coloured background.