Bug 35528: Remove 'click' from links in system preferences

Bug 35528: Remove 'click' from links in system preferences

It's not necessary to label a link with 'click', it being
a link and being formatted as such is enough.

This updates the occurences in the sytem preferences editor.

To test:
* Go to system preferences like OpacUserCSS that allow editing
  in a textarea
* Verify link descrptions for editing and collapsing the area
* For a section of grouped system preferences, hover over the
  arrow and verify the text for collapsing/uncollapsing the area
* Apply patch, restart all
* Verify the links and tool tips have been updated

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>