Ensure Thor temp directories are cleared up on fatal crash/pod termination

If Thor processes crash or if the pod is evicted, they leave their temporary used files orphaned.
Ensure they are deleted via lifecycle.preStop and post command scripting.

The temp dir used is not known until the process starts up, it then is assigned a worker number and uses this as a basis for the temp dir name.

Write this to a constant filename, such that the postStop/scripts can read it and clear it up if it still remains.