xmlui: Add CIP theme

Initial work done by Sisay Webshet (@swebsheet).

Signed-off-by: Alan Orth <a.orth@cgiar.org>
xmlui: Update CIP theme with new DSpace 4.2 Mirage assets

Signed-off-by: Alan Orth <a.orth@cgiar.org>
xmlui: Adjust space for item list in CIP theme

Signed-off-by: Alan Orth <a.orth@cgiar.org>
xmlui: Normalize fonts in CIP theme

11px is a bit too small, let's normalize 12px for all body text for
now.

Signed-off-by: Alan Orth <a.orth@cgiar.org>
xmlui: Tweak CIP theme to match corporate website more

Font stack, link and text color, heading colors, backgrounds, etc.

Signed-off-by: Alan Orth <a.orth@cgiar.org>