Currently Code Checker does not allow code formatted like so:

$foo->func1()

    ->func2()

    ->func3();

This is not widely used in Moodle code, but it could with adoption of 3rd party libraries and it is often used with mocks in PHPUnit.

Goals of this ticket:

1. Agree how we do support it (-> aligned vs existing wrapping rules).
2. Decide if we allow it globally (+1) or restricted to tests dirs (-1).
3. Implement it in the coding style documentation and code checker.