csis: Add debugdump

Coordinated Set Service Client:
  Groups
    == id: 1 ==
    uuid: 0000xxxx-0000-1000-8000-00805f9b34fb
    desired size: 2
    discoverable state: 0
    current lock state: 0
    target lock state: 0
    devices:
        == addr: xx:xx:xx:xx:xx:x1 ==
        csis instance: data:
          No csis instance available
        Connected conn_id = 8
    == id: 2 ==
    uuid: 00000000-0000-1000-8000-00805f9b34fb
    desired size: 2
    discoverable state: 0
    current lock state: 0
    target lock state: 0
    devices:
        == addr: xx:xx:xx:xx:xx:x1 ==
        csis instance: data:
          rank:
        Connected conn_id = 8
        == addr: xx:xx:xx:xx:xx:x2 ==
        csis instance: data:
          rank:
        Connected conn_id = 264
    == id: 3 ==
    uuid: 0000xxxx-0000-1000-8000-00805f9b34fb
    desired size: 2
    discoverable state: 0
    current lock state: 0
    target lock state: 0
    devices:
        == addr: xx:xx:xx:xx:xx:x2 ==
        csis instance: data:
          No csis instance available
        Connected conn_id = 264

Bug: 150670922
Tag: #feature
Sponsor: jpawlowski@
Test: compile

Change-Id: Id999aaec29946f4831d72f33f27730b20c9440a4