Added terraneo folder

Update CI job name to hog

* single precision builds do not work with hardcoded double - switching back to real_t
* casts are required inside the tabulation initializer lists

See HFG for details.

* HFG updated to 27578ea8116ca0920c88bc0da76f366448559a37 to support gradient.
* Generated new operators (diffusion (P2), gradient, divergence)
* Regenerated epsilon, full_stokes (with and without icoshell blending) after fixing trial and test swap and component passing.