Implement ListJobs in Controller with tests

Implement ListJobs in Controller with tests

Implementation enhances JobsController interface and implementation.
The mockup of JobsController is regenerated using:
    mockgen -source=controller/jobscontroller.go \
        -destination=controller/mock/jobscontroller.go \
        -package mock \
        -imports ".=git.tizen.org/tools/weles"

Tests for both JobsControllerImpl and Controller are updated.

Change-Id: Ie30234ac754d19616ce2811e3f30a6834d28e296
Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>