GDA-5479 Add test program to reproduce Jython server problems by interrupting threads

* Strip stuff out of GDAJythonInterpreter to allow it to be used in a test
  program
Merge remote-tracking branch 'origin/project/GDA-5479' into 8.34
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-core.git into 8.34