feat(go): implement Go leader redirection scenario

[chengxilo]

go leader redirection scenario implement

What I did

1. Implement Go leader redirection scenario and related logic.
2. Rearranged package layout to avoid cyclic dependencies introduced by the redirection logic.
3. Renamed package iggycli → client (clarifies that this is the Iggy client, instead of CLI)
4. New types like TransportEndpoints implement MarshalBinary/UnmarshalBinary(implement encoding.BinaryMarshaler/ encoding.Unmarshaler interface) instead of create a function like SerializeTransportEndpoints/DeserializeEndpoints. We may replace the previous approach later.

Notes

1. Package rename: code importing iggycli must update to client
2. Replace the DeserializeXXX/SerializeXXX with implmenting MarshalBinary/UnmarshalBinary in the future.

[hubcio]

Trying to find someone to review it.

[hubcio]

LoginUser has leader redirection logic, but LoginWithPersonalAccessToken does not

[hubcio]

malformed packet with nodesCount = 0xFFFFFFFF would attempt to allocate memory for 4 billion slots, limit it to max 10 nodes or so

[hubcio]

if disconnect fails after IncrementRedirect() was called, the redirect counter remains incremented but no redirection actually occurred.