* for an ingress with session affinity cookie, set the location as path on the cookie when unique
* the previous behaviour ( cookie path=/ ) is preserved for ingresses with multiple rules for the same backend (locations not unique)
added e2e tests for session affinity, setting path on sticky config
added tests:
* it should set the path to /something on the generated cookie
* it should set the path to / on the generated cookie if there's more than one rule referring to the same backend
