NoUnsetOnPropertyFixer - refactor and bugfixes

[kubawerlos]

Replaces #4020
Fix #3843

[SpacePossum]

Looking good!

For completeness, can you extract tests from these cases;

<?php

function a()
{
    return [1 => 2];
}

unset(a()[b()['a']]);
unset(a()[b()]);
unset(a()['a']);
unset(a(){'a'});

function c(&$a)
{
    return $a;
}

$a = new \stdClass();
$a->a = 1;
unset(c($a)->a);

var_dump($a);
die;

[keradus]

Thank you @kubawerlos.