ext/intl: Reset IntlChar error state on method entry - #22500

* PHP-8.5:

  ext/intl: Reset IntlChar error state on method entry (#22500)

* PHP-8.4:

  ext/intl: Reset IntlChar error state on method entry (php#22500)

Introduce PHP_INTL_FUNCTION_WITH_ERROR_RESET macro to standardize
and automate the global Intl error state reset at the start of
every userland PHP_FUNCTION. Also change the IC_METHOD function
to automatically reset error state in the start of the defined function.

The macro wraps the function entry point, performs
intl_error_reset(NULL), and delegates the actual logic to a
separate _impl function. This reduces boilerplate and prevents
bugs caused by missing error resets, as seen in GH-22931 and
GH-22500.

This refactor applies to all functions with a manual reset call
and does not affect internal helper functions that handle errors
independently.

IntlChar methods could leave stale global intl error state after a later successful call.

Reset the intl error state when entering each IntlChar method so successful calls report U_ZERO_ERROR.

Closes php#22500

* PHP-8.4:

  ext/intl: Reset IntlChar error state on method entry (php#22500)

* PHP-8.5:

  ext/intl: Reset IntlChar error state on method entry (php#22500)