Distributed moment fitting

[pmartorell]

@ericneiva

The moment fitting integration is not currently working on distributed.

I have done some progress in my fork distributed_moment_fitting but still do not work properly.

The integration is OK if all the cells are cut, but still an issue for the interior cells. I reckon there are some repeated contributions. I had not the time to fully debug this part. But I hope this developments are useful if you want to continue in the future.

Also note that the contributions of the face on the ghost cells are moved to the owner. This part is not strictly necessary since the assembly already move the contributions. Feel free to keep of remove these communications.

[ericneiva]

Okay, noted @pmartorell, thank you so much for your hard work :)