This is an update of the site registration admin page and some relevant
backend code to remove the mentions of moodle.net.
AMOS BEGIN
CPY [registerwithmoodleorg,core_admin],[registerwithmoodleorg,core_hub]
AMOS END
Support for alternative hubs will be removed in 3.4
We can move all methods working with registration, course publishing and moodle.net
communication into separate namespace