shim context getTask error is ignored

The context.getTask() call returns a Task struct and an error. In all cases either the task is nil or the error is nil. The error returned is also fixed and does not provide any detail not known without it (i.e. "application is not found" which only partially covers the cases)

We need to bring the call in line with GetApplication and the GetNode in the cache and just return the task and handle the nil return.