Add caller information to Begin execute log entry

This patch adds a new caller information logged by executor when a new MuranoPL
function is started. This will help to reconstruct a calls flow for debugging. Also it can
be used to create a graphical execution trace.

Change-Id: If53634994b99b9bdf68dd1a020f61abbbf656d4e
Merge "Add caller information to Begin execute log entry"