[Discussion] Add Filter\Filter and Filter\Flag Enums to the Filter Extension

Hi internals,

I would like to start an RFC for adding Filter\Filter and Filter\Flag
backed enums to the filter extension.

The proposal adds type-safe and more discoverable alternatives to the
existing integer filter and flag constants.

The existing constants and integer arguments remain supported for backward
compatibility.

The implementation is available here:
https://github.com/php/php-src/pull/24111

I would appreciate feedback on the API, naming, and overall approach before
preparing the RFC.

Thanks,
Muhammed Arshid KV