[NAN] Re-factor connect/config flow

Simplify flow: configure and connect in a single call.
Prevent info leak: no longer provide configuration back to caller.
Update error status codes

Bug: 27617910
Bug: 27553226
Bug: 27579450
Bug: 27674927
Change-Id: Id7aba816a074dbbe0cb188cfe498c97dccbdcb27