* Move seal barrier type field from Access to autoSeal struct.
Remove method Access.SetType(), which was only being used by a single test, and
which can use the name option of NewTestSeal() to specify the type.
* Change method signatures of Access to match those of Wrapper.
* Turn seal.Access struct into an interface.
* Tweak Access implementation.
Change `access` struct to have a field of type wrapping.Wrapper, rather than
extending it.
* Add method Seal.GetShamirWrapper().
Add method Seal.GetShamirWrapper() for use by code that need to perform
Shamir-specific operations.
* OSS portion of wrapper-v2
* Prefetch barrier type to avoid encountering an error in the simple BarrierType() getter
* Rename the OveriddenType to WrapperType and use it for the barrier type prefetch
* Fix unit test
* upgrade vault dependency set
* etcd and grpc issues:
* better for tests
* testing
* all upgrades for hashicorp deps
* kubernetes plugin upgrade seems to work
* kubernetes plugin upgrade seems to work
* etcd and a bunch of other stuff
* all vulnerable packages upgraded
* k8s is broken in linux env but not locally
* test fixes
* fix testing
* fix etcd and grpc
* fix etcd and grpc
* use master branch of go-testing-interface
* roll back etcd upgrade
* have to fix grpc since other vendors pull in grpc 1.35.0 but we cant due to etcd
* rolling back in the replace directives
* a few more testing dependencies to clean up
* fix go mod vendor
* rename some seal migration tests
* add comments to seal migration tests
* add comments to seal migration tests
* rename sealhelper
* creat TestSealMigration_ShamirToTestSeal
* fix typo in test suite
* create TestSealMigration_TransitToTestSeal
