Suggestion: Remove ConfigurationManager.AppSettings requirement

[nwgaeagle]

In the SecureNetRestApiSDK.Api.Controllers.BaseController.ProcessRequest method, there's a hard-coded requirement that the apiContext.Config dictionary pull its definition from the web/app.configs

In order to handle multiple SecureNet clients, it'd be nice if the code calling the ProcessRequest method can override the apiContext from their own codebase.

I suggest a flag of some sort to prevent the apiContext parameter from being overwritten or allow for only null apiContext to be overridden.