Remove the need to visit every page and extract the origin url by introducing a parameter url_prefix. The origin url is in format <prefix>/<repo_name> where The prefix is same for all the repos for a particular cgit instance.
Some cgit instance have a pagination. Modifiy lister to find all the pages and list all the repos from all the pages.
Implemented a lister to list the repos for a given CGit instance. Closes T1659