A high performance IoTDB-Restful API

[jixuan1989]

Is your feature request related to a problem? Please describe.

As IoTDB has been integrated in KMX, which uses REST API to communicate with IoTDB, a restful api with high performance is needed.

Besides, I think it is also useful for some other applications.

Describe the solution you'd like

running a restful service by using IoT-SQL and forward it to IoTDB Thrift RPC is inefficient, I think.
Therefore, I think a native restful service is better.