Is your feature request related to a problem? Please describe.

I'm always frustrated when we can't check something container-level.

Describe the solution you'd like

Smth. like VerifySignature(cid interop.Hash256, msg []byte, sigs []Signature, curveHash NamedCurveHash) bool, we need to:

• use https://pkg.go.dev/github.com/nspcc-dev/neo-go/pkg/interop/native/crypto#VerifyWithECDsa internally
• implement M/N internally precisely following the container placement policy (Extend container contract with node lists #412), each REP X should be satisfied by one of the appropriate nodes

This can be used both in contracts and verification scripts (with CID fixed). A set of signatures like this can prove object existence (refs. nspcc-dev/neofs-api#299).