add discovering mvp

[KaymeKaydex]

What has been done? Why? What problem is being solved?

I didn't forget about (remove if it is not applicable):

• [ ] Tests (see documentation for a testing package)
• [ ] Changelog (see documentation for changelog format)
• [ ] Documentation (see documentation for documentation style guide)

Related issues:

[KaymeKaydex]

@oleg-jukovec can u check this one please? just like model and idea of discovery

[oleg-jukovec]

1. It won't work like this because a replication pear address a some internal address which clients should not work with. In Tarantool 3 the situation is better and you can get this value from the config:

https://www.tarantool.io/en/doc/latest/reference/configuration/configuration_reference/#configuration-reference-iproto-advertise-client

2. But we already have a private library for Tarantool 3 for such purposes: https://github.com/tarantool/go-discovery
3. This pool does not work with a replicaset. It is a simple pool of connections to which you can add and remove connections. It is a flexible scheme and I would not like to change it. Autodiscovery is better implemented in a separate library based on this pool.