Add method_chaining_indentation rule

[samuelmaudo]

This PR recovers a rule to indent chained methods consistently.

With this rule, this code:

$user->setEmail('voff.web@gmail.com')
         ->setPassword('233434');

becomes:

$user->setEmail('voff.web@gmail.com')
    ->setPassword('233434');

It was included in the PHP CS Fixer ruleset, so if we replace it by the Symfony ruleset, it might be interesting to include it in our ruleset.