[PfemFluid] Add thermal coupling files

[MZecchetto]

Just that. Few notes:

• requires [PfemFluid] Add constitutive laws #6504;
• implements the last part of PFEM Fluid improvements GiDInterface#713;
• maybe small changes will be required to suit the GiD interface;
• preliminary test is enabled by default;

Massimiliano

[ipouplana]

Hi @MZecchetto , why have you modified DamApplication files here ?

[MZecchetto]

I never modified Dam files. now it should be ok

[ipouplana]

I see that you are adding CLs here... I guess that you have the same changes as in PR #6504, right?
If so, I would first merge that PR and then, once you merge the updated master branch over this one, you can merge this PR too. Was that your idea ?

[MZecchetto]

Yes, this is also my idea. I rebased this branch onto #6504 because I needed it. It was not 100% clear to me how the rebase is managed in a PR.