Refactor Jmx support, add attributes, shorten implementation

[artem-v]

Motivation:
Shorten jmx support in the code. Don't scatter jmx functionality over many classes, keep MBean in one class.

After update:

jmx-term gives following:

$>info
#mbean = io.scalecube.cluster:name=Cluster@3f87e86f7a9c483e
#class name = io.scalecube.cluster.monitor.JmxClusterMonitorMBean
# attributes
  %0   - AliveMembers (java.lang.String, r)
  %1   - ClusterConfig (java.lang.String, r)
  %2   - ClusterSize (int, r)
  %3   - Member (java.lang.String, r)
  %4   - MemberIncarnation (int, r)
  %5   - Metadata (java.lang.String, r)
  %6   - RemovedMembers (java.lang.String, r)
  %7   - SeedMembers (java.lang.String, r)
  %8   - SuspectedMembers (java.lang.String, r)

All monitoring attributes are gathered in a single MBean class.