[Feature] Use the OpenSpeedTest Server

[vinii8817]

Is your feature request related to a problem? Please describe.
No, it is not related to any problem.

Describe the solution you'd like
I would like the platform to be able to use OpenSpeedTest as a target server, which would allow scheduled tests within my own infrastructure.

Additional context
Nothing more, everything seems fine to me. ;-)
Ref: https://openspeedtest.com/

[alexjustesen]

Now tracking in #976