This PR was squashed before being merged into the 4.3-dev branch (closes #28898).

Discussion
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[Console] Add dumper

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #...   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | symfony/symfony-docs#10502

This PR adds a new `Dumper` helper in the Console component. As there are 2 types of dumps

- debug purpose (e.g. `dd()`, `dump()`)
- output purpose (see #24208, #27684)

For the latter we cannot use the global system (debug) dumper, i.e. `VarDumper::dump()`, we need something tied to the current output and dependency free. Here it is:

```php
$io = new SymfonyStyle($input, $output);
$dumper = new Dumper($io);

$io->writeln($dumper([-0.5, 0, 1]));
$io->writeln($dumper(new \stdClass()));
$io->writeln($dumper(123));
$io->writeln($dumper('foo'));
$io->writeln($dumper(null));
$io->writeln($dumper(true));
```

With VarDumper comonent:

![image](https://user-images.githubusercontent.com/1047696/47069483-4cc26f80-d1ef-11e8-902e-2f9b0f040f25.png)

Without:

![image](https://user-images.githubusercontent.com/1047696/47069517-6663b700-d1ef-11e8-9328-ae1db0b83d7e.png)

> #27684 (comment) var-dumper is not a mandatory dep of fwb, can we do without?

Now we can  :)

Commits
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fc7465c [Console] Add dumper