Reorganize composer scripts to be more visible

[llaville]

With current version of the composer.json user scripts are difficult to see when we run composer command without argument (to get help).

We should run composer run-script --list to see them

scripts:
  analyse  Use "phpstan" to the analyse static code. See phpstan.neon
  check    Check the coding covention and run the tests
  cs-check Use "phpcs" to check the coding convention. See phpcs.xml
  cs-fix   Use "phpcbf" to fix the coding convention. See phpcs.xml
  test     Use "phpunit" to run the tests. See phpunit.xml

I propose to apply namespace on composer command, like I did on project overtrue/phplint.

Gain: only one command to run composer and you will distinct standard composer commands and user scripts