Focus ring fails colour contrast

[derekjohnson]

Need

As a user of assistive technology
I want site content and interactions to be clear
So that I can use the website without unnecessary obstacles

Description

The blue focus highlight for the buttons and link has insufficient contrast of 2.4:1 against the grey background and 1.1:1 against the green button background.

Acceptance criteria

• the focus ring around the link and buttons in the consent banner passes colour contrast tests

Related: https://github.com/barnardos/website/issues/1725