Add method to resolve container name

[KirillovDenis]

It would be nice to have some way to resolve container name. Now we can know container ID by name using NNS resolver from SDK.

Having new way to resolve names in API would be helpful for:

• gates (they don't need to make rpc to sidechain)
• neofs-cli (we can easily find out container id by its name)

There are two way to adopt such resolving:

• Add new rpc mehod here
• Teach node to get containers not only by ID but also by name (It seems quite complicated and)

Probably this issue is for the future though.

/cc @alexvanin @realloc