reduce buffer size of "unused" side of socket

[gregcusack]

Follow Up to PR: #3929

Problem

We allocate large send and receive buffers for all sockets. However, not all sockets read and write equally from/to their buffers. In fact, 6 sockets are primarily Read and 2 are primarily Write. Meaning we are allocating memory that is never used.

Summary of Changes

1. TPU write side of sockets are only QUIC control traffic. Set buffer size to 4 MB
2. Broadcast and Repair read side of sockets are only QUIC control traffic. Set buffer size to $ MB

Services/Sockets
Read/Write

Gossip
RPC - TCP
Ip_echo - TCP
Tvu
tvu_quic
Repair
Repair_quic
Serve_repair
Serve_repair_quic
Ancestor_hashes_requests_quic
Ancestor_hashes_requests
Primarily Read

Tpu
Tpu_forwards
Tpu_vote
Tpu_quic
Tpu_forwards_quic
Tpu_vote_quic
Primarily Write

Retransmitter
Broadcast

Follow Up PR:

1. Make better sizing decisions for the sockets that don't need a full 128MB buffer

[steviez]

Ahh, this one slipped through the cracks. I doubt it will make any difference, but can you please rebase to tip as a precaution. I'm guessing your branch is on two-month-old-tip-of-master right now

[gregcusack]

Ahh, this one slipped through the cracks. I doubt it will make any difference, but can you please rebase to tip as a precaution. I'm guessing your branch is on two-month-old-tip-of-master right now

rebased!

[alexpyattaev]

testing on unstaked mnb node does not reveal any adverse impacts. will start on testnet, if all goes well I'll merge it in the morning.

[alexpyattaev]

ok tested on staked node, TPU works fine, LGTM!