Add dcmanager system-peer management api.
Test Plan:
1. PASS - Verify that cloud manage system-peer
through api successfully.
2. PASS - Run the add command without providing the password
and verify that the CLI asks for it.
3. PASS - Run the add with every possible parameter and verify
all of them were successfully passed to the backend.
4. PASS - Verify dcmanager help output the correct help messages
for each command.
CLI example:
dcmanager system-peer add --peer-uuid 800503ca-21c1-40b2-9425-88319185fe61
--peer-name dc-0 --manager-endpoint http://128.128.128.1:5000/v3
--peer-controller-gateway-address 192.168.205.1
(peer's uuid from the peer site `system show` command)
dcmanager system-peer list
dcmanager system-peer update --administrative-state enabled 1
dcmanager system-peer show 1
dcmanager system-peer delete 1
Story: 2010852
Task: 48487
Depends-On: I349cd24bccc732eb8ed56df9346185cfce7b2570
Change-Id: I7ea22991d8ea879af7401e10b058e7ee44cd6a8d
Signed-off-by: Zhang Rong(Jon) <rong.zhang@windriver.com>