Add support for GitHub Enterprise Server for GitHub Integration #12836
Description
Is your feature request related to a problem? Please describe
Currently enabling the github integration for the system does not allow the github integration for a product to create and update issues on an on-prem GitHub Enterprise Server installation as the default is always to use github.com and there is no (at least none that I can find) way to configure the URL for the GitHub server.
Describe the solution you'd like
Adding a GitHub Integration should by default use github.com as it does today, but allow for the ability to override the URL for use those wishing to integrate with on-prem GitHub installations.
Describe alternatives you've considered
I dug through the code and as far as I can see there is no alternative solution, all calls to the main class for PyGithub do not specify a base_url see here
Additional context
After a very cursory glance, I think it could be as simple as adding a field to GITHUB_Conf for base_url, with a default from PyGithub DEFAULT_BASE_URL = "https://api.github.com"
And then subsequently changing all instances of calls to the Github class to include the parameter base_url e.g. g = Github(g_conf.api_key, base_url=g_conf.base_url)