token: update structure

This commit:

  * moves Token message to service package;

  * updates token structure (new verb field, some renaming);

  * replaces VerificationHeader header with Token in object package;

  * removes no longer used VerificationHeader message.

session/types.proto

@@ -1,35 +0,0 @@
-syntax = "proto3";
-package session;
-option go_package = "github.com/nspcc-dev/neofs-api-go/session";
-option csharp_namespace = "NeoFS.API.Session";
-
-import "github.com/gogo/protobuf/gogoproto/gogo.proto";
-
-option (gogoproto.stable_marshaler_all) = true;
-
-message VerificationHeader {
-    // PublicKey is a session public key
-    bytes PublicKey = 1;
-    // KeySignature is a session public key signature. Signed by trusted side
-    bytes KeySignature = 2;
-}
-
-// User token granting rights for object manipulation
-message Token {
-    // Header carries verification data of session key
-    VerificationHeader Header = 1 [(gogoproto.nullable) = false];
-    // OwnerID is an owner of manipulation object
-    bytes OwnerID = 2 [(gogoproto.customtype) = "OwnerID", (gogoproto.nullable) = false];
-    // FirstEpoch is an initial epoch of token lifetime
-    uint64 FirstEpoch = 3;
-    // LastEpoch is a last epoch of token lifetime
-    uint64 LastEpoch = 4;
-    // ObjectID is an object identifier of manipulation object
-    repeated bytes ObjectID = 5 [(gogoproto.customtype) = "ObjectID", (gogoproto.nullable) = false];
-    // Signature is a token signature, signed by owner of manipulation object
-    bytes Signature = 6;
-    // ID is a token identifier. valid UUIDv4 represented in bytes
-    bytes ID = 7 [(gogoproto.customtype) = "TokenID", (gogoproto.nullable) = false];
-    // PublicKeys associated with owner
-    repeated bytes PublicKeys = 8;
-}