Add async streaming for replication to improve replication speed

[meskill]

The current replication process is strictly sequential with parallelization only between multiple shards. Every event runs the cycle send -> wait for response that can slow the whole process significantly especially with high latency on read.

Rework the process to push the updates without waiting for response immediately and read the responses asynchronously in separate task to react on possible errors.

[yogesh1801]

@meskill for this can we extend ParallelConnection which COPY already uses?

[meskill]

@meskill for this can we extend ParallelConnection which COPY already uses?

probably, it allows to write and read data async, we just need to properly handle the responses during replication and advance lsn only after we get response on multiple shards.

[yogesh1801]

Wll try this issue