Remove config.Config from wiki package

As we are ready to get rid of the global config.Config variable this change does exact it for the files in the wiki package. It also includes refactoring: addition of the setup functions, renames and marking functions as test-helpers. All ruby sidecar dependent tests are assembled into a single one as a sub-test. It uses a single instance of the ruby service created internally. The global rubyServer variable and initialisation code are removed as they are not unused anymore.

Part of: #2699 (closed)