Bug 32571: (follow-up) Implement abstracted tabs on About page

Bug 32571: (follow-up) Implement abstracted tabs on About page

This patch implements the proposed system for building tabs on the About
page.

To test, apply the patch and view the About page. It should look the
same as before and all tabs should function correctly.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 1398f1180ca6867cbf8a6f2dec4861496eb8a8f1)
Signed-off-by: Jacob O'Mara <jacob.omara@ptfs-europe.com>