this is included till plumed 2.9

Also with some minor cleanups of the code and docs.

This option should solve once for all the problem with gnu unique symbols.
I am not 100% this option will not introduce troubles linking other C++
libraries, and thus I leave the possibility to remove it with
./configure --disable-no-gnu-unique

However, problems are very unlikely considering that this is the
same behavior of icpc and clang.

See plumed#549

* Test with and without MPI

* WALKERS_MPI now throws without MPI initializated

* test and error message now are more clear

* clearer comments in the tests

* added the last newline to the new files

* PlumedHasMPI is now a function

* camelCased plumedHasMPI

* style aligned

* moved files

* created compiledtest type

* compiled tests now support align with the other tests

* Moved the new test in the basic directory

* now the new test is completely aligned with the old ones

* removed compiled test

* updated the reference

---------

Co-authored-by: Daniele Rapetti <[email protected]>

Fix 95cc6eb / 6ac01e2
also allows me to include this update that was still blocked.

added the reusable workflows

* removed the actionRegister shortcut from bias

* removed the CLTollRegister shortcut from cltools (why that is in core and not in cltools?)

* Again removed some shortcuts to actionRegister.h

* removed the ActionRegister.h shorcuts

* rectified the style changes due to clang-format

* now compiles

* updated the changelog for developers in the 2.10

---------

Co-authored-by: Daniele Rapetti <[email protected]>

Proposal for mklib.sh modification

small changes in the openMP settings

Co-authored-by: Mattia Utichi <[email protected]>

* patch updated to fix plumed#960

@GiovanniBussi the fix works but i do not know if it does
what you need there

* removed wrong files from patch

* gromacs 2023.2

hrex fix should be closer to previous behavior
but likely still not functional

adding a comment to explain the new piece of code

corrected F90 error and patched the wanted version of qe

@Iximiel I removed unrelated changes

@maxbonomi you need to add an example otherwise the CI test fails.

I temporarily add a placeholder