refactor: Dashboard support for users grouped by extId

[JoVictorNunes]

What does this PR do?

This PR refactors the Learning Dashboard for supporting the grouping by extId rather than intId. Only one row per user will be displayed in the tables.

Motivation

With #13826, the info will be stored using extId rather than intId. So, this PR adds the necessary Dashboard changes for matching that implementation.

[gustavotrott]

Hey @JoVictorNunes, it is working very well!

I will need to ask you to make just one adjustment.
There is a case when one user can join the meeting from different devices at the same time. In this case, we want two rows in the Dashboard.. cause it would be a mess to merge/handle two webcams simultaneously, two devices speaking and so on...
In short, we can have two users using the same extId and because of that we can't use the extId as key to summarize anything (e.g usersActivityScore[a.extId]).
There is a new prop called userKey that is unique and can be used instead.

I am attaching an Json with this case.
learning_dashboard_data.zip

[sonarcloud]

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6 Code Smells

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0.0% Duplication

[gustavotrott]

LGTM!

[gustavotrott]

LGTM!