Refactor cluster_info module to reduce complexity of the code

[KirillLykov]

Problem

cluster_info module has the following problems:

• too much code in one module -- for example, maybe move Node to it's own file?
• Node has several constructors which have some differences but I'm sure there is a space for consolidation
• Sockets structure is flat, so it spits sockets by names. For example, tpu_ and later these fields are used to construct structure TpuSockets. Extract structures with proper construction encapsulation.
• in new_localhost_with_pubkey_and_quic_endpoints we sometime bind to 0.0.0.0 and sometimes to localhost.
• Encapsulation -- remove pub from fields:

pub struct Node {
    pub info: ContactInfo,
    pub sockets: Sockets,
}

[KirillLykov]

@alexpyattaev Created an issue while looking into it. Might be a good starting issue for a new comer.

[alexpyattaev]

struct Sockets is definitely on their way towards net-utils so we can have all socket binding related code in more or less one place. It can be neatly split off from Node initialization. PR for that