Add colour to status progress percentage

[hugovk]

Purpose

Add more colour to the logs, so the "[XX%]" bit is shown in a different colour based on percentage, from red to green:

reading sources... [ 49%] extdev/nodes
...
writing output... [ 97%] usage/restructuredtext/directives
...
highlighting module code... [100%] sphinxcontrib.websupport.storage
...
copying images... [100%] _static/themes/bizstyle.png

Demo using:

uv run --group docs --no-group package make -C doc clean html

I verified no colour is shown when disabling via env var:

NO_COLOR=1 uv run --group docs --no-group package make -C doc clean html

AI Disclosure

Initial code by Claude, improved by me.

[hugovk]

CI failure unrelated, should be fixed by #14611 or #14669.