Add west --color=always and west config color=always

[marc-hb]

Git has an (somewhat inconsistent) set of "color = always" options to override the automated terminal detection. Demo of one of the (too many) options:

git diff                            # colored           :-)
git diff                | less      # not colored       :-(
git diff --color=always | less  -R  # colored again!    :-(

It would nice for west to offer the same feature.

While rarer, color=never is sometimes needed too. For instance some CI engines try hard to pretend they are terminals to capture colors but then can fail to display them for some reason.

[marc-hb]

Originally posted by @marc-hb in https://github.com/zephyrproject-rtos/west/pull/649#discussion_r1169274807

In west, colorama handles terminal detection. The following and BARELY TESTED hack seems equivalent to color=always

--- a/src/west/app/main.py
+++ b/src/west/app/main.py
@@ -895,7 +895,7 @@ def main(argv=None):
 
     # Makes ANSI color escapes work on Windows, and strips them when
     # stdout/stderr isn't a terminal
-    colorama.init()
+    colorama.init(strip=False)
 
     # Create the WestApp instance and let it run.
     app = WestApp()

west diff | less -R # color!
west diff | less    # as expected, color mojikabe :-(

[marc-hb]

An interesting question design is: when git and west settings conflict, which one wins?

git config color.ui never
west config color always

west diff | less -R # color or not?

To make things even more interesting, git has not just one color.ui setting but also another color.status and who knows what else.

[marc-hb]

Spotted by @mbolivar-nordic:

• https://lwn.net/Articles/929123/ Textual: a framework for terminal user interfaces