metacontroller should have a separate examples repo with proper e2e

[AmitKumarDas]

No description provided.

[sathieu]

@AmitKumarDas What is the difference between this bug and #4?

@grzesuav What about creating a metacontroller-contrib repo with user-contributed controllers? I've re-iplemented istio ingress conversions to gateway and virtualservice (because istio/istio#31817 was not accepted), and this would fit in it.

Not sure e2e tests are needed, but testing controllers against predefined inputs is definitively needed.

[AmitKumarDas]

@sathieu This issue as well as #4 are pointing to same stuff. I was thinking to put these as two separate repos since library mode will be typical Golang based & will reduce the learning curve in the long run.

Note: metacontroller still does not support library mode. So contrib repo can be started off.

[grzesuav]

@sathieu I am more keen to set up #85 for this purpose - as I do not think we will support all user-written controllers with their custom logic etc and offer bug fixing and feature requests - but we sure can put a place which can point to all that.

Also, this issue started at the beginning of migration, I am not sure how suitable would be to have metacontroller in one repo and e2e tests in the other as it will be a problem to keep it in sync, and intorducing changes to both in the same time and still having tests passing