Update related stopParticipantGroup to take only groupId argument #520
Description
With ParticipantRepository.getRecruitmentWithParticipantGroup, recruitment containing a specified StagedParticipantGroup can be retrieved with the groupId, and studyId is no longer needed.
This is introduced at #519, and used for inviteParticipantGroup, stopParticipantGroup no longer need studyId besides validation.