* Fix matching on extension attrs and predicates
* Fix detection of match_id when using extension attributes. The match
ID is stored as the last entry in the pattern. We were checking for this
with nr_attr == 0, which didn't account for extension attributes.
* Fix handling of predicates. The wrong count was being passed through,
so even patterns that didn't have a predicate were being checked.
* Fix regex pattern
* Fix matcher set value test
* Add custom MatchPatternError
* Improve validators and add validation option to Matcher
* Adjust formatting
* Never validate in Matcher within PhraseMatcher
If we do decide to make validate default to True, the PhraseMatcher's Matcher shouldn't ever validate. Here, we create the patterns automatically anyways (and it's currently unclear whether the validation has performance impacts at a very large scale).
