[BUG] csharp - oneOfStringArray and oneOfString not compiling to code properly. Sample config attached.

Description

I just downloaded the latest generator tool and when generating csharp-netcore instead of creating the right schema it creates the type OneOfstringArray as an invalid "type". To be clear, everything gets created but there are a few fields that do not compile when opening up the solution so I have to edit them manually. I know oneOf isn't fully supported yet, want to keep this issue open to keep visibility on it.

THANKS FOR ALL THAT YOU DO!

openapi-generator version

4.3.0

OpenAPI declaration file content or url

Components -> schemas section 

https://gist.github.com/thedonmon/da508473db9c02942afa47a7c3ad1e4a

Command line used for generation

openapi-generator generate -g csharp-netcore -i "schema.json"

Steps to reproduce

run command above, open solution file, try to build the project and see where the errors point to the "Invalid type OneOfstringarray" or "OneOfstring"

Related issues/PRs

https://github.com/OpenAPITools/openapi-generator/issues/2311

Suggest a fix

Either the json schema on my end needs to be cleaned up or there needs to be a way to combine the two types. I believe I can help locate the issue need to dig into the code to see how to handle this scenario.

Start with the OpenAPI declaration in the linked gist and reproduce it using schema.json with the shown csharp-netcore generation command. Inspect the generated solution for the invalid OneOfstringArray and OneOfstring types; done means the generated C# project builds without those compilation errors.