Add a Python wrapper
Description
Adds a Python wrapper which should support the following features:
- generic requests formed and sent from Python,
- response times measurements,
- subscriptions with the following restriction:
- as in the LibSub extension, only one subscription per connection is available, which lifecycle is linked to the LibSub connection lifecycle, and all monitored items are added to this single subscription.
This extension shall be written in Python3 using CFFI to interface the S2OPC and LibSub libraries.