Removing get_node_power_state, bumping RPC version

There is a periodic task that is used to check the power state and save it to
the DB. Users can query the DB instead of checking the machine. Also removing
the RPC call and bumping RPC_API_VERSION to 1.10.

Closes-Bug: #1277062
Change-Id: I87923eee8f88e85e621fd0bf839d99250788561f