Constants as openapi const

[apasquini95]

As mentioned in #1015, the OpenApi 3.1 standard allows to declare constant values with the const syntax, instead of using the single-value enum schema. This can improve openapi readability and parsers' interpretation of it.

This merge request allows the developer to use this feature, that can be enabled by toggling the scramble.class_constants_as_const config value.

[romalytvynenko]

I'm wondering, is this PR AI-assisted??

I don't understand why this pr introduces so much changes across all subsystems (type inference, open api generation, configuration) while the only thing it should do is to use const JSON schema keyword when transforming literal types to JSON schema.

[apasquini95]

No, no AI was involved. I tried to figure out how to do it by following the EnumCaseType's lifecycle. The configuration was just a plus, since I thought it could be an unnecessary or even unwanted feature for some developers. If you have any suggestion to make it better, I'd be glad to update the PR.

[romalytvynenko]

@apasquini95 gotcha.

I believe that this PR should be only concerned with 2 things: 1) add const keyword to json schema (generator type), 2) ensure that single literal type is represented with const, not enum.

I see you also attempted changing how class consts fetching work, but there is no need for it. And if in some context it doesn't work, it is a completely different issue then.

[apasquini95]

Ok, I'll make another attempt thanks :) What about the configuration flag? Do you think it is unnecessary?

[romalytvynenko]

@apasquini95 nah, I'd rather just go for it. const is much better representation of literals

[romalytvynenko]

@apasquini95 thanks!