Split OnEvent(membership_event)

Splitting OnEvent(membership_event) into

• OnMembershipAdded
• OnMembershipRenewed
• OnMembershipRemoved would be easier to read. (dispatch instead of match)

changed milestone to %runtime-800

mentioned in merge request !215 (merged)

added P7-nicetohave RN-runtime labels

@HugoTrentesaux maybe we can postpone it to runtime-801 ?

changed milestone to %runtime-801

changed milestone to %runtime-802

mentioned in merge request !246 (merged)

assigned to @bgallois

closed with merge request !246 (merged)