Refactor outlier detection configuration fields

[csssuf]

Title: Refactor outlier detection config message fields

Description:
As discussed in #8130 (comment), the outlier detection configuration fields are a bit messy and could use a cleanup. The main work here is to de-dup all of the options into a common message around enabled, local origin split, etc. and then hopefully just have a single field per actual ejection type. This would avoid an explosion of almost identical fields for each different ejection type.

[mattklein123]

Fixed in #8221

[csssuf]

Oops, I see now that I used the wrong title in this issue, sorry! My understanding based on the linked PR comment was that there's some refactoring of the OutlierDetection message itself that's desired; #8221 was more of a mechanical fix.

[mattklein123]

Oh right, sorry, let me reopen and I will add some more detail.

[mattklein123]

I updated the issue description a bit to hopefully have a bit more info.

[htuch]

I think we should create the new outlier config in v2 and then deprecate the existing one, making the v3 bump a mechanical transition. Marking as help wanted, since this needs implementation work.