Added validation example for Problem 3.x of Class (2009)

[jafranc]

This PR is following #1723 in adding a validation case on Johansen mesh as proposed in the third problem (Problem 3.x) of the benchmark paper: "A benchmark study on problems related to CO 2 storage in geologic formations", Class et al, 2009.

The mesh data has been stored in GEOSX_DATA 's Dataset and is associated with PR 10.

The missing part are:

• [x] find a way of imposing boundary condition ( constant hydrostatic pressure gradient and temperature gradient) on the set of boundary cells
• [ ] extract and compare data to Figs. 9 and 10 using TimeHistory

[jafranc]

Changed from layer of cell boundary to face boundary. Changed from TimeHistoryOutput to extraction of reservoirStatictics from log.

Still few things to fix in plotting script.

During DocDay we discussed about the thermal problem, and we think it should be in a partII in its own PR. Let me know if you agree 😃

[jafranc]

Many thanks for cleaning/merging it @francoishamon :)