Output of surface flux uses the standard mesh
output. Therefore it isn't necessary anymore to
pass the output_directory.

Mv porosity/storage from solid to medium properties.

- Forward the output folder and mesh vector from ProjectData to CreateLiquidFlow.
- Create an optional SurfaceFluxData object.

If only file name is specified it causes a warning
about the name not to be specific enough if there is
another file with the same name, e.g.:

the name `IdealGasLaw.h' supplied as the second argument
in the \file statement matches the following input
files: ogs/MaterialLib/Fluid/Density/IdealGasLaw.h
ogs/MaterialLib/MPL/Properties/IdealGasLaw.h
Please use a more specific name by including a (larger)
part of the path!

From now on only \file w/o a name or a full path will
be allowed.

find -type f | xargs sed -i 's%\(\\file\).*%\1%'

The main change was in the creation of liquid flow process;
the succeeding changes are just adoptation to a pointer,
instead of a reference with boolean.

This versions check if the PropertyVector is
assigned to the requested mesh item type and has
the required number of components.

Clang format run on near-the-header lines.

Happy New Year

Especially on iterator types and 'new' allocations.

This allows for correct documentation of the process_variables.