Feature/activate multiple users

[idelcano]

📌 References

• Issue: http://who-dev.essi.upc.edu:8083/issues/2598

🎩 What is the goal?

• Clean the list of actions in training config file.
• Activate multiple users in groups of 50 instead of one by one.

📝 How is it being implemented?

I have modified the api call from /users/ID to use the metadata endpoint like user advanced app.

💥 How can it be tested?

Run the script with the action:
{
"selectFromGroups": ["ADMIN reactivate after cloning"],
"action": "activate"
}