OpenAPI: Allow configuration of name of generated files

[AndreasPetersen]

Description

If we set quarkus.smallrye-openapi.store-schema-directory Quarkus will generate a openapi.yaml and openapi.json file in the specified directory.

Our organisation has a requirement that these files must have a specific name, which is not openapi. We would like a new config option to change the name of the generated files.

Implementation ideas

A new configuration property, e.g. quarkus.smallrye-openapi.file-name, that determines the name of the generated OpenAPI files.

[quarkus-bot]

/cc @EricWittmann (openapi), @MikeEdgar (openapi), @phillip-kruger (openapi), @radcortez (config)