Emit warning when the input .toml file overwrites the cell configuration in a .pdb file

[antoinewdg]

Right now this happens completely silently.
Implement something like there

lumol/src/input/src/simulations/system.rs

Lines 54 to 58 in 8ee3657

	warn!(
	"No unit cell in the system, using an infinite unit cell.\n\
	You can get rid of this warning by using `cell = []` in the \
	input file if this is what you want."
	);

.

[Luthaf]

This need to work not only for PDB files, but for any file with an unit cell: NetCDF, TNG, ...

In order to do this, we can check if the system has a non-infinite unit cell before setting the cell from the input, and send a warning in this case.

[antoinewdg]

Do we have a way to test that input files generate a warning in the tests of the input crate ?

[Luthaf]

No, not yet. it should be easy to add to the test framework by using a custom logger and checking the messages at warning level.