[Legacy] function + function calls to static methods and static calls

## Before

```php
# some_utils_class.php

function some_function()
{
}

some_function('lol');
```

## After

```php
# some_utils_class.php

class SomeUtilsClass
{
    public static function some_function()
    {
    }
}

SomeUtilsClass::some_function('lol');
```

