qapi: Enforce event naming rules

Event names should be ALL_CAPS with words separated by underscore.
Enforce this.  The only offenders are in tests/.  Fix them.  Existing
test event-case covers the new error.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-14-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
11 files changed