With fake noreply and support users, the notifications were not accessible by user
Support for viewing messages from noreply user has been added.
Signed-off-by: Rajesh Taneja <rajesh@moodle.com>
This is used by messaging system for sending/receiving message
to/from noreply or support user. message_send api will now use
core_user class to get noreply or support user and then
send/receive message depending on user state.