Allow passing WorkflowContext and TaskContext to input, output, export function for experimental lambda

[fjtirado]

Currently, java functions that are invoked by input, output and export, only accepts the workflow model. In order to achieve their purpose of refining the model context, they might need additional information (the same that is available to JQ expression). This information is contained in WorkflowContext and TaskContext, which might be optional extra parameters to the invoked function if user desire so.