Bug 33928: Improve translation of title tags: Various

Bug 33928: Improve translation of title tags: Various

This patch updates various templates so that title tags can be more
easily translated. Some templates have been updated for consistency as
well: Harmonizing page title, breaddrumb navigation, and page headers.

To test, apply the patch and confirm that the following pages have the
correct title tags:

- Staff interface -> Log in
  - Staff interface home page
  - Error page (e.g. for a missing page 404 error)
  - About page

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>