core: Move encryption utilities to utils

We have only two utility classes in the engineencryptutils project, and
they fit will in the utils project.

Change-Id: Idc40671d65d8f47d051302506a7a64f7b1240b33
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>
(cherry picked from commit d70b98882fedecac0130d5e9486ea7a8901f1dd1)