Add `context.Context` as a param to `engine`'s operations

[carpawell]

It would look natural and even now it already has an application.

[carpawell]

https://github.com/nspcc-dev/neofs-node/issues/2480, whoops. Close or treat as a sub-part.

[cthulhu-rider]

#2480, whoops. Close or treat as a sub-part.

this issue a little wider, so lets keep both