Start adding backend for group member hook

Use group member data builder

app/models/concerns/triggerable_hooks.rb

@@ -15,7 +15,8 @@ module TriggerableHooks
     wiki_page_hooks:          :wiki_page_events,
     deployment_hooks:         :deployment_events,
     feature_flag_hooks:       :feature_flag_events,
-    release_hooks:            :releases_events
+    release_hooks:            :releases_events,
+    member_hooks:             :member_events
   }.freeze
 
   extend ActiveSupport::Concern

app/models/members/group_member.rb

@@ -63,6 +63,8 @@ class GroupMember < Member
 
   def post_create_hook
     run_after_commit_or_now { notification_service.new_group_member(self) }
+    add_group_member_data = Gitlab::HookData::GroupMemberBuilder.new(self).build(create)
+    group.execute_services(add_group_member_data, :member_hooks)
 
     super
   end

app/models/service.rb

@@ -86,6 +86,7 @@ class Service < ApplicationRecord
   scope :pipeline_hooks, -> { where(pipeline_events: true, active: true) }
   scope :wiki_page_hooks, -> { where(wiki_page_events: true, active: true) }
   scope :deployment_hooks, -> { where(deployment_events: true, active: true) }
+  scope :member_hooks, -> { where(member_events: true, active: true) }
   scope :alert_hooks, -> { where(alert_events: true, active: true) }
   scope :deployment, -> { where(category: 'deployment') }
 

ee/app/models/hooks/group_hook.rb

@@ -20,7 +20,8 @@ class GroupHook < WebHook
     :pipeline_hooks,
     :wiki_page_hooks,
     :deployment_hooks,
-    :release_hooks
+    :release_hooks,
+    :member_hooks
   ]
 
   belongs_to :group