[Console] Add threshold for ProcessHelper verbosity
[FrameworkBundle] Use ProcessHelper for server:run command
feature #11135 [FrameworkBundle] Use ProcessHelper for server:run command (romainneutron)

This PR was merged into the 2.6-dev branch.

Discussion
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[FrameworkBundle] Use ProcessHelper for server:run command

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT

Let's use our new process helper :)

Commits
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6ca1c90 [FrameworkBundle] Use ProcessHelper for server:run command
a5f36a8 [Console] Add threshold for ProcessHelper verbosity