Send invitation to an admin user

`This endpoint allows you to invite a member to manage the Admin account

Features and their respective permissions are as below:

• my_plan:
  • "all"
• api:
  • "none"
• user_management:
  • "all"
• app_management | Not available in ENTv2:
  • "all"

Note:

• If all_features_access: false then only privileges are required otherwise if true then it's assumed that all permissions will be there for the invited admin user.