Order dependency of atoms when running alexandria gentop

When running alexandria gentop, the code relies on the input PDB file having the same order as the MolProps file.

The PDB looks like:
```
AUTHOR Andersson2023
CRYST1 30.000 30.000 30.000 90.00 90.00 90.00 P 1 1
HETATM 1 H HF 1 5.030 4.970 4.099 1.00 0.00 H
HETATM 2 F HF 1 5.226 4.991 3.192 1.00 0.00 F
HETATM 3 H HCl 2 14.867 4.886 3.766 1.00 0.00 H
HETATM 4 CL HCl 2 14.811 5.011 2.487 1.00 0.00 Cl
HETATM 5 H HBr 3 4.853 14.905 3.683 1.00 0.00 H
HETATM 6 BR HBr 3 4.902 14.686 2.269 1.00 0.00 Br
HETATM 7 H HI 4 14.723 13.110 4.462 1.00 0.00 H
HETATM 8 I HI 4 15.466 13.681 3.145 1.00 0.00 I
CONECT 1 2
CONECT 2 1
CONECT 3 4
CONECT 4 3
CONECT 5 6
CONECT 6 5
CONECT 7 8
CONECT 8 7
END
```

And the MolProps file (mp2-aug-cc-pvtz.xml for those who can access it) has this order for hydrogen fluoride.
```

1 2



-0.2141315114000122


0
0
0.0
0
0
-0.187573118


0
0
0.813208
0
0
0.187573118


...

```

Gives rise to the following error:
``````
-------------------------------------------------------
Program: alexandria gentop, version 2020-dev-20240729-a4f8659d2-unknown
Source file: fragmenthandler.cpp (line 271)
Function: bool alexandria::FragmentHandler::setCharges(const chargeMap&)

Error in user input:
Atom mismatch when reading charges from chargemap for InChI=1S/FH/h1H.
Expected H but found F. Make sure the atoms in your chargemap match those in
your molprop file.

For more information and tips for troubleshooting, please check
the ACT website at https://github.com/dspoel/ACT/wiki
-------------------------------------------------------
```