[Console] added a Process helper
[Console] Add process helper tests
feature #10627 [Console] added a Process helper (fabpot, romainneutron)

This PR was merged into the 2.3-dev branch.

Discussion
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[Console] added a Process helper

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/3930

This PR replaces #10609.
I've fixed minor errors, added tests and allowed to pass an array of arguments to escape as a command

Commits
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edc1bfe [Console] Add process helper tests
faffe7e [Console] added a Process helper