CIF controller checker: allow multiple checks to conclude partial confluence for a single event pair

Instead of requiring that all occurrences of an event-pair must fit in a single confluent pattern, allow occurrences to be matched by one or more patterns.

In terms of implementation, take all occurrences and check against the available patterns. After checking against a pattern remove the occurrences that were matched, and continue checking the remaining patterns with the occurrences that failed to match.

Confluence of an event-pair can then concluded when all occurrences were removed due to matching a pattern.