Implement filtered worker listing

Implement filtered worker listing

WorkerList first applies Capabilities (Caps) and then Group filter.
Currently Caps require exact match, i.e. all keys must be found and
values must be equal. It is planned to support ranges and lists
of values.

Change-Id: I705c7b2f3e7a0be5506c5e6cfef5cd32af274fc9
Signed-off-by: Aleksander Mistewicz <a.mistewicz@samsung.com>
Reviewed-on: https://mcdsrvbld02.digital.local/review/49061
Reviewed-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Tested-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
Reviewed-by: Maciej Wereski <m.wereski@partner.samsung.com>
Tested-by: Maciej Wereski <m.wereski@partner.samsung.com>