initial implementation of tmap_1db

[rekomodo]

Contributes to #33 .

[RemDelaporteMathurin]

Hi @rekomodo I did some changes to improve the performance:

• reduced the size of the problem
• only have a small stepsize around the breakthrough time
• optimised mesh

The trapped concentration gradients are extremely steep. And this produces oscillations:

This is something you often see with this case and is called Gibbs phenomenon. Refining the mesh helps, sometimes using DG elements for traps helps too (but here it seems to be making things worse).

This is why you have this little wave on the rise of the flux curve. I don't really know how to get rid of this tbf