[LEBV-20] Waiting screen

🎯 Summary

✨ Waiting screen and videoconference ✨

Run in a terminal this branch.
Execute the agent portal in the branch LEBV-124-videocall (check https://gitlab.mobbeel.com/MobbScan-Integration/lebara-video/lebara-video-agent-portal/-/merge_requests/2).
Run the latest backend.
Open in one tab http://localhost:4200 (Customer) and http://localhost:4300 (Agent) in another one.
Introduce the following credentials in the agent part: csuarez / lebara.
If the agent is "Unavailable", click in the button to set it as "Available".

Complete the registration process, including passing the pre videoconference step (the video call language should be "English").
A waiting queue page will appear until an agent accepts.
Accept the call in the agent part (a notification should appear)
The video call should start in both sides.
In the agent part click in "Accept" or "Reject" to finish the call.

This has been implemented on a rush, some behaviours could be buggy. Let's decide in the MR what is fixed here or in new tickets.

Edited Jun 04, 2020 by César Suárez