fdo#84573 COLOR PICKER: Improve keyboard navigation

Change-Id: Iae9d6b96114732950800c323013f7fbb531053f2
Reviewed-on: https://gerrit.libreoffice.org/12253
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>