Update GVEC-related code, and replace all renamed `extract_pform()`
- Adapt GVEC-related tests to new directory structure of
mhd_equil
. - Add dummy test file for 3D polar splines, based on
test_template_gvec
. - Add dummy ParaView support.
- Since
extract_pform()
was renamedextract_p()
, do "Replace All". - Reinstate deleted changes in
domain_3d
. - Document
Tensor_spline_space
'sextract_p()
functions. - Fix broken
projectors_global
intest_divB
. - Rename
extract_0form_vec()
toextract_0()
.