[Icons] Need Icons for Online / Offline Instances

[pickypg]

For every component in the stack, we can sometimes detect three states in various parts of the UI:

• Online
• Offline
• Probably Offline (e.g., haven't heard from it in awhile, but we do have some data in the selected time range)

Looking through the existing icons, I think that check or checkInCircleFilled and bolt are probably the closest thing to representing the first two, but I do not see a good one for the third one. Possibly reusing compute in some way that didn't depend on color may also help.

[cchaos]

@pickypg Why wouldn't you use EuiHealth with "Online", "Offline", "~Offline" written out explicitly?

[pickypg]

That's a possibility, but it limits our ability to display different concerns. That is literally what we do currently (but we have historically used gray for the offline variant):

but I think that this may cause confusion with other parts of Elasticsearch and Kibana where the status color itself has meaning. A "green" online node may be confused as Elasticsearch is green for that node (which is not a thing).

This is compounded for Kibana, which actually has a colored state per instance, which would be different from the ~Offline status at least and Offline as well because that's something that we would be inferring.

I suspect that these three types of icons would also be useful for various management UIs, particularly anything that deals with a third party service to show the varying states.

[cchaos]

@pickypg Icons have shipped with latest release

[pickypg]

Nice, thanks! /cc @justinkambic @ycombinator @ruflin @tsullivan for awareness relative to future efforts.