Respecting JSONEncoder's keyEncodingStrategy

[jcbriones]

Issue: Found an issue where when I use theOpenAPIEncodedSchemaType.openAPISchema(using encoder: JSONEncoder) to create a JSONSchema with passing an encoder that has keyEncodingStrategy set to convertToSnakeCase, the JSONSchema's keys wasn't converting the keys to use convertToSnakeCase and returning as what the variable name is set to.

How to reproduce:

1. Create a JSONEncoder with the following:

let encoder = JSONEncoder()
encoder.keyEncodingStrategy = .convertToSnakeCase

2. Create a sample model

struct SampleObject: Codable, Sampleable, OpenAPIEncodedSchemaType {
    let sampleKey: String
    let sampleValue: String
}

3. Initialize the model with any values and use the SampleObject's openAPISchema(_:) to generate the schema.
4. Verify the keys of the model as sampleKey and sampleValue instead of sample_key and sample_value.

Expected: The expected result should be having the keys as sample_key and sample_value.

[mattpolzin]

This is interesting. Fundamentally the JSONEncoder passed in is used as sparingly as possible during reflection, but I can see how you would want (and reasonably expect) the encoder's settings to be respected RE things like key encoding strategy.

This seems like a worthwhile thing to fix, though I am not sure when I will get the time to tackle it.

Thanks for reporting!

[jcbriones]

Yeah of course! Wanting to help improve this! It really is useful