Missing field from convertpw4qmc output triggers ion checkup

**Describe the bug**

QMCPACK crashes with
`ERROR Primitive cell ion 0 vs supercell ion 0 atomic number not matching: 0 vs 74`
because `atomic_number` cannot be read from an orbital file created by `convertpw4qmc`.

The source of `convertpw4qmc` contains comments regarding future implementation of the field, but it is currently needed in `src/QMCWaveFunctions/EinsplineSetBuilderESHDF.fft.cpp`. It seems possible to override abortion by hardcoding `skipChecks=True`, but I haven't tried it.

**To Reproduce**
The problem occurs e.g. in a simulation of W atom with a noncollinear QE trial using QMCPACK 3.10.0. Input files to reproduce are attached, but convert4qmc needs to be executed after QE.

**Expected behavior**
Convertpw4qmc is expected to provide `atomic_number`, so that the QMCPACK checks pass.

**System:**
Cades batch node

[converter_problem.zip](https://github.com/QMCPACK/qmcpack/files/5681102/converter_problem.zip)