Clean up full-scale test Python application

[baagaard-usgs]

Description

The full-scale test Python application is getting clunky.

• Computing the solution fields should get the time stamps from the PyLith output not hardwired into Python module for the solution.
• Debugging test failures often requires editing the Python scripts to add more diagnostic information

Desired Solution

• Get time stamps from the PyLith output
• Allow display of the L2 norm of the “error”.
• Make it easier to debug failures (add a hook for loading the Python debugger for plotting)