Adapt Swagger type mapping to OpenApi 2.0

[Peter-B-]

This PR fixes #856.

Microsoft.OpenApi 2.0 introduced some breaking changes and while #844 addressed them in GenerateCodeForAspNetCoreOpenApiSchema, this PR adapts GenerateCodeForOpenApiSchemaCustomization.

I moved OpenApiVersionBeingUsed and OpenApiSchemaUtils to top level and adapted the generation code.

It works with both OpenApi 1.x

global::Microsoft.Extensions.DependencyInjection.SwaggerGenOptionsExtensions.MapType<global::WebApplication.Shared.SharedStruct>(o, () => new global::Microsoft.OpenApi.Models.OpenApiSchema { Type = "integer", Format = "int32", Nullable = false });
global::Microsoft.Extensions.DependencyInjection.SwaggerGenOptionsExtensions.MapType<global::System.Nullable<global::WebApplication.Shared.SharedStruct>>(o, () => new global::Microsoft.OpenApi.Models.OpenApiSchema { Type = "integer", Format = "int32", Nullable = true });

and OpenApi 2.x

global::Microsoft.Extensions.DependencyInjection.SwaggerGenOptionsExtensions.MapType<global::WebApplication.Shared.SharedStruct>(o, () => new global::Microsoft.OpenApi.OpenApiSchema { Type = global::Microsoft.OpenApi.JsonSchemaType.Number, Format = "int32" });
global::Microsoft.Extensions.DependencyInjection.SwaggerGenOptionsExtensions.MapType<global::System.Nullable<global::WebApplication.Shared.SharedStruct>>(o, () => new global::Microsoft.OpenApi.OpenApiSchema { Type = global::Microsoft.OpenApi.JsonSchemaType.Number | global::Microsoft.OpenApi.JsonSchemaType.Null, Format = "int32" });

I added a new OpenApiMode to the Consumers WebApplication and WebApplication.Shared projects. They support MicrosoftAndScalar, Swashbuckle-net8, and Swashbuckle-net10. I'm not sure about the naming, though.

Please review this PR carefully, since I do not have a comprehensive understanding of Vogen or Source Generators in general :-)

[SteveDunn]

Thank you for the PR! I'm working in this area at the moment, but won't be able to finish for a while, but I'll get around to this PR as soon as possible. Thanks again, much appreciated!

[Peter-B-]

Thanks for the feedback. If I should adapt anything, please let me know.

Take your time - it's your free time after all.

Thanks for investing it in this project!

[Peter-B-]

Hi @SteveDunn,

I tried to rebase on your latest changes, but I broke it and cannot figure out why. I get build errors:

Vogen.ValueObjectGenerator\_MapVogenTypesInOpenApiMarkers_g.cs(30,140): error CS0234: The type or namespace name 'OpenApiOptions' does not exist in the namespace 'Microsoft.AspNetCore.OpenApi' (are you missing an assembly reference?)

I don't understand what is happening and I didn't manage to find the generated file. I think I need some support here.

[Peter-B-]

I took another look at the issue and managed to fix it.
Please let meknow, if you see any issues. Otherwise, I can update the Snapshots.

[SteveDunn]

Thank you! I should have time to look at it over the weekend.
Thanks again for your contribution!

[SteveDunn]

LGTM! Thanks for the great work! I've merged this and will rebase the snapshots in the next commit.