Add typed events for all group hooks and legacy events

[ChristophWurst]

Continuation of #18225

• Add typed events
• Emit events where we emitted legacy events and/or hooks
• Catch new events and re-emit data as legacy events and/or hooks

• preAddUser (\OC\Group\Group $group, \OC\User\User $user)
• postAddUser (\OC\Group\Group $group, \OC\User\User $user)
• preRemoveUser (\OC\Group\Group $group, \OC\User\User $user)
• postRemoveUser (\OC\Group\Group $group, \OC\User\User $user)
• preDelete (\OC\Group\Group $group)
• postDelete (\OC\Group\Group $group)
• preCreate (string $groupId)
• postCreate (\OC\Group\Group $group)

-> existing code should continue to work, but new code can use the typed events with 18+

[ChristophWurst]

Integrated as #18350. The clean up has to be done on a french branch, I guess