Add a python port

• This MR is a feature complete port from perl to python
• The python version will only build on el8/el9, cc7 will still get the perl port
• This port utilises python-requests, against the REST api of lxkerbwin (instead of the legacy XML)
• Interaction with kerberos credentials are been deliberately performed with kinit subprocess calls to minimise code complexity and software dependencies (also because it's not actually possible to do all required calls with python-gssapi 🙃 )
• An image-ci workflow has been implemented along with puppet manifests and scripts to test all supported features