Need to support "show child nodes (prefix)"

[qiaojialin]

Suppose we have some timeseries:
root.turbine1.1701.sad123
root.turbine1.1702.sad123
root.turbine1.1703.sad123

"show child nodes root.turbine1" should return

1701
1702
1703

[HTHou]

It's as same as the issue #2493...

[qiaojialin]

Haha, thanks~