Lists requests to join a group.
Note: This function is only relevant for private groups.
The listjoinGroupRequests() function returns a Promise that resolves to a list of up to 100 requests to join a group. Sorts by default to _createdDate in descending order.
Only site admins and group admins can see requests to join their group. Site members can access their own join requests in their site.
Notes:
ID of the group requested to join.