Improve types used with `Z_PARAM_STR`

[Jeckerson]

Instead of zval key; use zend_string struct.

See details here - phalcon/cphalcon#15792

[remicollet]

This now raises an error with GCC 14

See

• Broken build with GCC 14 [-Wincompatible-pointer-types] ice/framework#315
• Broken build with GCC 14 [-Wincompatible-pointer-types]  RubixML/Tensor#42
• [BUG]: broken build [-Wincompatible-pointer-types] phalcon/cphalcon#16531