REST API: Broker getContractList; NetworkMonitor getPeersList

Change-Id: I7ac6aecc7d64819324741e499c31d97eb06d957f
Reviewed-on: http://naan.mimuw.edu.pl:8001/97
Tested-by: Nebulostore Nebulostore <nebulostore@gmail.com>
Reviewed-by: Bolek Kulbabinski <bkulbabinski@gmail.com>