This is the OSS portion of enterprise PRs 1904, 1905, 1906, 1907, 1949,
and 1971.
It replaces the proxycfg manager's direct dependency on the agent cache
with interfaces that will be implemented differently when serving xDS
sessions from a Consul server.
And into token.Store. This change isolates any awareness of token
persistence in a single place.
It is a small step in allowing Agent.New to accept its dependencies.
* Increase number to test ignore. Consul Enterprise has more flags and since we are trying to reduce the differences between both code bases, we are increasing the number in oss. The semantics don't change, it is just a cosmetic thing.
* Introduce agent.initEnterprise for enterprise related hooks.
* Sync test with ent version.
* Fix import order.
* revert error wording.