Enable ShinyProxy authentication and deployment

[LDSamson]

Currently, there is a deployment option called noncredentialed in the config yaml file. This assumes deployment using Posit Connect:

riskassessment/R/app_server.R

Lines 55 to 60 in b91c6e3

	} else if (isFALSE(get_db_config("use_shinymanager"))) {
	res_auth <- reactiveValues()
	res_auth[["admin"]] <- FALSE
	res_auth[["user"]] <- session$user %||% "anonymous"
	res_auth[["role"]] <- intersect(unlist(session$groups, use.names = FALSE), dbSelect("select user_role from roles")[[1]]) %||% "default"
	} else {

For deployment with the latest version of ShinyProxy, different objects need to be used to read the user and group information from: Instead of session$user and session$groups it would be best to read from HTTP headers (should be something like session$request$HTTP_X_SP_USERID session$request$HTTP_X_SP_USERGROUPS).

It would be great if such a feature can be implemented. If you are interested I can help with that.