Run GEOS from install dir in experiment

[mathomp4]

This is part of a suite of PRs to try and change how we handle GEOSgcm.x in GEOS. The issue is that more and more of GEOS subcomponents are becoming shared object libraries instead of static.

Overall Problem

That means the old trick of "copy someone else's GEOSgcm.x to my experiment" might not work. Why? Well, in GEOSgcm v11.10+, the Moist GridComp (for example) is now a shared object library and so just copying GEOSgcm.x isn't enough to actually use that other person's Moist GC code.

What we change here

What we do now is copy into experiments a new install/bin and install/lib directory. The former has GEOSgcm.x as well as binarytile.x and rs_numtiles.x (as they are the main executables in the run scripts) and then all the .so into install/lib. We then update the scripts to use those executables.

Since CMake encodes in the executable's RUNPATH, $ORIGIN/../lib then if you run:

mpirun -np 6 $EXPDIR/install/bin/GEOSgcm.x

it will look for libraries it needs in $ORIGIN/../lib and that is just the lib/ dir at the same level as EXPDIR/install/bin.