Moving comments and JSON schema from glz::object for faster compilation (support moved to glz::json_schema)

[stephenberry]

Specializing a glz::meta that defines a value = glz::object(...) is very common for Glaze users. Even with reflection potentially coming in C++26 and the current aggregate initializable reflection, we will always need glz::meta or something like it in order to define changes to default reflection (like renaming, wrappers, glz::custom, and lambdas).

Right now glz::object supports passing in comments and glz::schema as the second or third argument for each field (depending on whether the field uses reflection on the member name).

This discussion is about removing the ability to add comments and glz::schema to the glz::object call. I am not proposing losing any functionality, only requiring users to move their documentation and JSON schema objects to glz::json_schema. With the introduction of glz::json_schema, we can now add comments and JSON schema information outside of glz::meta.

This simplification in what glz::object accepts will improve compile times for most users and simplify the code.

glz::object will still optionally support renaming members and registering wrappers and lambda functions. This change would only affect comments and JSON Schema.

Add your thoughts to this discussion. I don't want to make breaking API changes unless it benefits users long term. And, I think this would benefit users in the long term by simplifying the codebase and especially making compile times faster.

[stephenberry]

@jbbjarnason, what are your thoughts on this simplification and moving glz::schema out of the glz::object list?

[stephenberry]

I'm considering as a first step to simply remove glz::schema support from glz::object(...).