Automatic merge from submit-queue (batch tested with PRs 38592, 39949, 39946, 39882)

move api/errors to apimachinery

`pkg/api/errors` is a set of helpers around `meta/v1.Status` that help to create and interpret various apiserver errors.  Things like `.NewNotFound` and `IsNotFound` pairings.  This pull moves it into apimachinery for use by the clients and servers.

@smarterclayton @lavalamp First commit is the move plus minor fitting.  Second commit is straight replace and generation.