[Feature] Schedule Downtime/Pause

[svenvg93]

Is your feature request related to a problem? Please describe.
No not a problem

Describe the solution you'd like
I would love the have the ability to schedule "downtime time" or pause in the Speedtest tracker. Having the this abillity would allow to not run the scheduled test during a specified period,, for example ISP maintenance. Or to run the test but muted/disable the notifications.

With #1350 adding a Annotations automaticlly to the graphs for the schedule period, with a note.

Additional context
N/A

[danielsmith89]

Would also love this, I've got an ISP maintenance window coming up and would be great to be able to pause tests.