etcp: restore etcp_link_update_inflight_lim + state machine fixes + diagnostics
- etcp_link_update_inflight_lim: self-contained method with clamping,
send_blocked_inflight check, loadbalancer_link_ready on cwnd increase
- etcp_conn_on_inflight_lim_changed: recalc optimal_inflight + resume input
- etcp_ack_recv: use etcp_link_update_inflight_lim instead of manual set
- etcp_request_pkt: fix line 928 check old link (inf_pkt->last_link) not new
- etcp_link_close: recalc optimal_inflight on link removal (both branches)
- etcp_socket_remove: fix dangling pointer loop (nullify after close)
- uasync_print_resources: show timer names, remain time, deleted entries
- diagnostics in utun_instance_destroy and test_etcp_reconnect
DEBUG_INFO(DEBUG_CATEGORY_CONNECTION,"NEW link initialized on etcp=[%s] link=%p socket=%s id=%d is_server=%d mtu=%d",etcp->log_name,link,conn->name,link->local_link_id,link->is_server,link->mtu);
DEBUG_INFO(DEBUG_CATEGORY_CONNECTION,"NEW link initialized on etcp=[%s] link=%p socket=%s id=%d is_server=%d mtu=%d",etcp->log_name,link,conn->name,link->local_link_id,link->is_server,link->mtu);