Bug fixes for netconf southbound plugin.

Fixed wrong operation type sending in edit-config for netconf device. Action type replaced for "operation" type.
Fixed conversion of toRpcMessage in NetconfMapping. Fixed wrong QName - changed from "action" to "operation".

Change-Id: Ic9e07dfc2bdb50552321754cb92333ef88aa14bb
Signed-off-by: Lukas Sedlak <lsedlak@cisco.com>
Merge "Bug fixes for netconf southbound plugin."