Bug 36899: Make entire fieldset clickable

Bug 36899: Make entire fieldset clickable

To test:
1. APPLY PATCH
2. Regenerate CSS ( https://wiki.koha-community.org/wiki/Working_with_SCSS_in_the_OPAC_and_staff_interface )
3. Follow the test plan from bug 36864
4. Now the entire disabled fieldset should be clickable.
5. When the disabled fieldset is clicked from anywhere with it the fieldset should become enabled. The other one should then be disabled.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>