[27.x backport] Buffer 'docker stats' text to avoid terminal flickering

[vvoland]

• backport: Buffer 'docker stats' text to avoid terminal flickering #5586

This change reduces the flickering of the terminal when running docker stats by buffering the formatted stats text and printing it in one write.

Should also consume less CPU as we now only have to issue a single syscall to write the stats text to the terminal.

I suspect it fixes #4348, but I can not confirm since that issue was reported on WSL.

- What I did

On all of my Linux machines (Fedora Linux + GNOME) I can see terminal flickering when running 'docker stats'.

I've tested this with gnome-terminal/xfce4-terminal/xterm and it flickers on all. The only term that does not flicker is kitty.

I've also tested this on GNOME running Wayland and X11. I can see no difference in behaviour between Wayland/X11.

I've tested this on two machines: Thinkpad T14s gen1 running AMD zen, and a desktop PC running AMD zen chip with Radeon GPU. Both behave identically.

recording of the flickering:
https://github.com/user-attachments/assets/05f8278e-05c3-411e-bb32-dad262136937

'docker stats' used to issue multiple write calls to stdout. Starting with the "clear screen" command and following multiple small write requests.
I'm now bundling all of those into a single string that is then written out to the stdout as a single request.

This fixes the flickering (as well as reduces syscalls required for each update) on both of my machines.

I've tested this on Fedora 41 GNOME with the following terminal emulators: gnome-terminal/xfce4-terminal/xterm/kitty.

I've tried things like resizing the window as 'docker stats' was running. It all works flawlessly now :)

- Description for the changelog

`docker stats` output is now buffered to reduce flickering issues 

- A picture of a cute animal (not mandatory but encouraged)

A cat that sometimes roams outside my flat. Me and my flatmates call him Phantom 🐱

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 58.65%. Comparing base (6736be7) to head (470ab05).
Report is 6 commits behind head on 27.x.

Additional details and impacted files

@@            Coverage Diff             @@
##             27.x    #5588      +/-   ##
==========================================
- Coverage   58.66%   58.65%   -0.02%     
==========================================
  Files         345      345              
  Lines       29047    29053       +6     
==========================================
  Hits        17040    17040              
- Misses      11036    11042       +6     
  Partials      971      971              

[thaJeztah]

LGTM