Adds basic auth UI to OpenAPI / Swagger docs

OpenAPIConfiguration.java

@Configuration
@SecurityScheme(
        name = "basicAuth", // can be set to anything
        type = SecuritySchemeType.HTTP,
        scheme = "basic"
)
@OpenAPIDefinition(
        info = @Info(title = "Sample API", version = "v1"),
        security = @SecurityRequirement(name = "basicAuth") // references the name defined in the line 3 
)
class OpenAPIConfiguration {

}