[RCA Initiative] Events timeline filter system is in place

[jasonrhodes]

Acceptance criteria

• UX exists similar to the one shown above that allows filtering the following types of events
  • Alerts for [the rule type that the source alert was from]
  • Alerts for this entity (if possible to do by alert group by lookup)
  • All other alerts
  • Annotations for this entity (if possible to detect)
  • All other annotations
  • Maybe by type? e.g. "All deployment annotations" if we could set up annotations to work this way... (Q: what types are available, is this a wide open field or a fixed enum of choices)
  • Other filters we need to start?

Note: Some categories here may overlap, especially with alerts (an alert could be of a certain rule type AND related to this entity, etc) -- my suggestion would be to keep it simple and if the event matches ANY of the selected filters, we show it, and it only disappears from the timeline if it no longer matches any selected filter.

cc: @maciejforcone we will need your help figuring out how to navigate a basic version of this design, thanks!

[elasticmachine]

Pinging @elastic/obs-ux-management-team (Team:obs-ux-management)