Jenkins CI missing from ServicesApi

Reading and writing Jenkins CI settings are missing from the ServicesAPI.

@jabby can you confirm that from an implementation perspective JenkinsService (like JiraService) needs to be created and used in the ServicesApi?

Hello @hu-tmx I missed your message. Yes we need to add Jenkins CI the same way it is done for other services. Can you provide a PR for this modification?

I will try to do so once I find the time