Refactor: Rename FOREACH_{NODE,TICKET}.

Future commits will continue to get rid of uses of the global config
variables. Some of those uses involve these macros, so we need a
version of them that takes a conf argument as well.

This commit just temporarily renames those macros so not every caller
has to change. A later commit can introduce three argument versions of
these macros, and then we can move callers in several commits. When all
are moved, these renamed versions can go away.