Add support for pipelines with `|>` and `?|>`

[thekid]

This pull request implements support for https://wiki.php.net/rfc/pipe-operator-v3

Example

$user= $name |> trim(...) |> strtolower(...);

// Equivalent of:
$user= strtolower(trim($name));

See also

• #180
• https://github.com/xp-framework/ast/pull/52
• https://github.com/php/php-src/pull/17118