EPIC Integrate Telemetry into Element Call

[fkwp]

This is an epic issue. List of individual issues is below:

In order to gain insights into Element Call and to improve it we need proper information about general (daily) usage, conference size, and potentially other metadata (network loss, delay, cpu load). It should probably also allow us to see when calls fail (or individual calls fail in group calls) and give us enough diagnostic information to work out what went wrong, in a nice graph-like format.

• VoIP Anonymity Logic (EC Telemetry: Anonymity Logic #353)

[toger5]

Closing in favor of: #533