Replace `core/container.ErrNotFound` error returned by `Source.Get`
interface method with `apistatus.ContainerNotFound` status error. This
error is returned by storage node's server as NeoFS API statuses.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Make all operations that related to `neofs-api-go` library be placed in `v2`
packages. They parse all v2-versioned structs info `neofs-sdk-go`
abstractions and pass them to the corresponding `acl`/`eacl` packages. `v2`
packages are the only packages that do import `neofs-api-go` library. `eacl`
and `acl` provide public functions that only accepts `sdk` structures.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>