fix(engine): Improve PA-context-switch detection

Problem Description:

No context switch is performed if the process engine has already
performed a context switch and the classloader has been manipulated by
the container as a result of a cross application interaction (ie. EJB
local invocation).

Proposed Solution:

Record PA-Classloader after context switch has been performed. Compare
it to the TCCL upon subsequent invocations.

related to #CAM-2822