* Port over some SP v2 bits
Specifically:
* Add too-large handling to Physical (Consul only for now)
* Contextify some identity funcs
* Update SP protos
* Add size limiting to inmem storage
* Add key information to list endpoints in identity.
Also fixes some bugs from before where we were persisting data that we
should not have been (mount type/path).
* Add cached lookups of real time mount info
* Start work on passing context to backends
* More work on passing context
* Unindent logical system
* Unindent token store
* Unindent passthrough
* Unindent cubbyhole
* Fix tests
* use requestContext in rollback and expiration managers
* Doc updates and API refactoring
* fix tests
* change metadata fieldtype to TypeKVPairs
* Give example for TypeKVPairs in CLI for metadata
* Update API docs examples to reflect the native expected value for TypeKVPairs
* Don't mention comma separation in the docs for TypeCommaStringSlice
* s/groups/group; s/entities/entity; s/entity-aliases/entity-alias; s/group-aliases/group-alias
* Address review feedback
* Fix formatting
* fix sidebar links
* external identity groups
* add local LDAP groups as well to group aliases
* add group aliases for okta credential backend
* Fix panic in tests
* fix build failure
* remove duplicated struct tag
* add test steps to test out removal of group member during renewals
* Add comment for having a prefix check in router
* fix tests
* s/parent_id/canonical_id
* s/parent/canonical in comments and errors
