qa/tasks: add a template filter to map a role name to a remote

qa/tasks: add a template filter to map a role name to a remote

Add a `role_to_remote` template filter function that has the ability to
map a role name to a remote. Attributes of the remote can then be
used to get the actual node ip or name.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
(cherry picked from commit 361cbd46b9c5431452c742edd3ca7f0280e4161b)