Add vTune task API for worker threads

[mrks]

We just learned about the vTune task API. We could annotate the different operators so that we can identify what the worker threads are doing when Hyrise is working. This could look similar to this:

The API is described here:
https://software.intel.com/en-us/articles/using-new-task-api-feature-of-intel-vtune-amplifier-xe-2013