Add support of CLICOLOR to enable/disable colored output

[xdelaruelle]

Support of the CLICOLOR and CLICOLOR_FORCED environment variable, to enable or disable Modules colored output, has been requested.

CLICOLOR and CLICOLOR_FORCED is an attempted to define a standard way to control colored output enablement across command-line tools. Full reference: https://bixense.com/clicolors/

These variables will complement the MODULES_COLOR variable which is still needed to control colored output enablement at the Modules-scope only.