monitoring: implement owner routing for alerts
Created by: bobheadxi
Adds a new owners
field to observability.alerts
as proposed in #12010 for RFC-189. Only alerts that match the specified owners will be received by the associated notifier. Notifiers configured without the owners
field will continue to receive all alerts of the specified level, even with notifiers that have owners
present.
(outdated screenshot, but close enough)
Closes #12010 - the other half of the proposal was implemented in https://github.com/sourcegraph/sourcegraph/pull/12358
Still thinking about owners
vs onOwners