Compute worker monitoring for organizers and collaborators.

[IdirLISN]

@ mention of reviewers

@ObadaS
@Didayolo
@ihsaan-ullah

A brief description of the purpose of the changes contained in this PR.

This feature enables admin users, competition organizers and his/her collaborators to monitor compute worker activity (only default one for now).

Lastly added:
Feature available only for competition organizers and collaborators.
Disabled by default and hided behind button by default (top / right).
When disabled or hided behind the button, the websocket connection is disabled for performance.
The Button needs to be behind the user menu.

The feature is ready to be merged, if you think it is useful.

/!\ Deployed on dev instance so you can try it live. /!\

Issues this PR resolves

Enables organizers to monitor compute workers activity to push users to use their own workers in case of high activity on codabench compute workers.

A checklist for hand testing

• Try the panel as a organizer, you should be able to see it by pressing the button.
• Submit and watch if the panel shows the activity of the compute worker
• In a competition made by someone else, you should not be able to see the button and interact with it.
• Verify websocket state when the panel is not displayed, the connection should be deactivated.

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge

[Didayolo]

Hi @IdirLISN,

Thank for the PR. Don't forget to fix the formatting issues:

^@^@src/apps/competitions/tasks.py:842:9: F821 undefined name 'r'
src/apps/competitions/tasks.py:842:50: F821 undefined name 'json'
src/apps/competitions/tasks.py:843:9: F821 undefined name 'r'
src/apps/competitions/tasks.py:844:13: F821 undefined name 'WORKERS_REGISTRY_KEY'
src/apps/competitions/tasks.py:846:13: F821 undefined name 'json'
src/apps/competitions/tasks.py:852:41: W292 no newline at end of file
src/celery_config.py:42:1: E303 too many blank lines (3)
src/celery_config.py:47:2: W292 no newline at end of file
src/utils/consumers.py:60:17: W503 line break before binary operator
src/utils/consumers.py:61:17: W503 line break before binary operator
src/utils/consumers.py:77:23: W292 no newline at end of file