Ion-ion energy convergence in quasi-2D systems

**Describe the bug**
Reference ion-ion energy of a quasi-2D system (bilayer graphene 3x3x1 tiling at gamma) converges to an incorrect value for bilayer separation at 7 Angstroms.

Due to the mismatch between the reference and QMCPACK ion-ion energies, after printing "Checking ion-ion Ewald energy against reference", QMCPACK terminates. I have used ewald lr_handler with increasing kc cutoff up to 100. Despite the increased cutoff, the problem is not resolved. For the set of ion-ion energy results below, I have used ccecp potentials and LDA functional:

| kc_cutoff | QMCPACK | Reference | QE |
| ------------- | ------------- | ------------- | ------------- |
| 50 | 1131.3290657604 | 1131.2315948714 | 1131.32906586 |
| 75 | 1131.3290657129 | 1131.2315948714 | 1131.32906586 |
| 100 | 1131.3290656824 |1131.2315948714 | 1131.32906586 |

QE values are printed in Ry for the primitive cell, therefore they are adjusted by multiplying with 9/2 for the 3x3x1 tiled supercell.

In the legacy code, the error was printed at every run I tested:
```
ERROR in ion-ion Ewald energy exceeds 0.0003 Ha/atom tolerance.

Reference ion-ion energy: 1131.2315948714
QMCPACK ion-ion energy: 1131.3290657604
ion-ion diff : 0.097470889017131
diff/atom : 0.0027075246949203
tolerance : 0.0003
```
However, there were instances where the error was not printed in the batched code (see dmc folder in the attached files)

**To Reproduce**
Steps to reproduce the behavior:
1. Using QMCPACK 3.15.9 and QE 7.0
2. using complex legacy cpu and batched cpu variants
3. full program/test invocation command: srun -N 4 -c 32 --cpu-bind=cores -n 4 qmcpack_complex vmc.in.xml
4. additional steps: None

**Expected behavior**
Reference values in the table should match the QE and QMCPACK ion-ion values within some tolerance with increasing kc cutoff. Batched code should also print the error at every run if encountered.

**System:**
- System: Andes
- Module list: 1) gcc/9.3.0 2) openblas/0.3.17-omp 3) netlib-lapack/3.9.1 4) fftw/3.3.10 5) cmake/3.18.4 6) cuda/10.2.89 7) openmpi/4.0.4 8) hdf5/1.10.7 9) boost/1.74.0
- other systems where this is reproducible: none

**Additional context**
Add any other context about the problem here.
Input/output files:
[ewald_sum.zip](https://github.com/QMCPACK/qmcpack/files/11191059/ewald_sum.zip)