Add longhaul tests to feature lifecycle guidance requirements

[mukundansundar]

Should longhaul tests be added as a requirement for API lifecycle to become stable?
Additionally what is the guidance for adding longhaul tests?

[mukundansundar]

cc @halspang @tanvigour @msfussell @dapr/maintainers-dapr

[tanvigour]

@mukundansundar I have put up a proposal attached to this issue, for proposed improvements based on discussion between, me,Hal and John and based on what came out of the discussion in the forum the other day.

I completely agree we need some guidance around writing Longhaul tests. What should that entail, should be decided once we know what Longhauls in this space should exactly be shooting for in terms of metrics. As far as having longhauls as requirement for stability of API lifecycle is concerned, do you think there's a gap that conformance and certification tests do not cover and longhauls do which is required for the stability?