Changes

add pySim.esim.es9p with definitions of the ES9+ HTTP Interface

Let's use the infrastructure of pySim.esim.http_json_api to define
the ES9+ API Functions.  This can in turn be used by clients or even
osmo-smdpp can be ported over to using this infratructure rather than
open-coding a lot of the encoding/decoding of API request/response
parameters.

Change-Id: I194ef1d186391f36245c099cc70a4813185ecf9c