cli: add node uuid in rebalance and remove brick status xml output

This patch adds node uuid in rebalance/remove-brick status xml output.
Output XML will look like

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput>
  <opRet>0</opRet>
  <opErrno>0</opErrno>
  <opErrstr/>
  <volRebalance>
    <op>3</op>
    <nodeCount>1</nodeCount>
    <node>
      <nodeName>localhost</nodeName>
 ==>> <id>883626f8-4d29-4d02-8c5d-c9f48c5b2445</id>
      <files>0</files>
      <size>0</size>
      <lookups>0</lookups>
      <failures>0</failures>
      <status>3</status>
      <statusStr>completed</statusStr>
    </node>
    <aggregate>
      <files>0</files>
      <size>0</size>
      <lookups>0</lookups>
      <failures>0</failures>
      <status>3</status>
      <statusStr>completed</statusStr>
    </aggregate>
  </volRebalance>
</cliOutput>

Change-Id: Ie2eb6e8d024605326d1a710b7c40ee30139f0f22
BUG: 1012296
Signed-off-by: Bala.FA <barumuga@redhat.com>
Reviewed-on: http://review.gluster.org/6032
Reviewed-by: Kaushal M <kaushal@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>