Implement no-flow-control extension

### Description

Implement support for the "no-flow-control" SSH extension, per [RFC 8308](https://tools.ietf.org/html/rfc8308#section-3.3).

### Motivation

This may bring some improvements on networks with high latency.

### Alternatives considered

Growing the window size is an alternative, but requires a global modification on the server side and can not only affect file transfers.

### Additional context

_No response_

Start by reading RFC 8308 section 3.3 and locating Apache MINA SSHD's existing SSH extension negotiation paths. Trace both client- and server-side handling to determine where the no-flow-control extension belongs. Done means the extension is supported according to the RFC and covered by relevant tests, though the issue does not name specific files or tests.

Written by the indexing model from the issue text.