This commit changes SegmentsRepository::getWPUsersSegment() so that it
behaves like Models\Segment::getWPSegment() and creates a WP segment
when none is found. This is needed to replace the latter with the former
in a subsequent commit.
[MAILPOET-4306]
Remove the following errors:
(Method|Property|Function) has no (return )?type specified.
(Method|Function) has parameter with no type (specified).
I have modified bulkDelete to be similar to bulkDelete on SubscribersRepository.php. This function is used in MailPoet\Test\API\JSON\v1\Segments.
[MAILPOET-3720]