Update NEXUS examples to use batched drivers

Many of the Nexus examples either use the legacy drivers or do not have a batched equivalent. In nearly all cases this will only require updating the requested driver to "batched", but the outputs do need to be checked.

(Reported by Ilkka, found via QMC classes/tutorials)

> At nexus/examples command "grep -ir legacy *" gives
>
> qmcpack/rsqmc_misc/H2O/H2O.py: driver = 'legacy',
> qmcpack/rsqmc_misc/H2O/H2O.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond/diamond.py: driver = 'legacy',
> qmcpack/rsqmc_misc/oxygen_dimer/oxygen_dimer.py: driver = 'legacy',
> qmcpack/rsqmc_misc/oxygen_dimer/oxygen_dimer.py: driver = 'legacy',
> qmcpack/rsqmc_misc/LiH/LiH.py: driver = 'legacy',
> qmcpack/rsqmc_misc/LiH/LiH.py: driver = 'legacy',
> qmcpack/rsqmc_misc/H2O_pyscf/h2o_ae_hf_vmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond_pyscf/diamond_pp_dft_gamma.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_excitation_alternatives.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_opt_tiling.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc_opt_tiling.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/excited/vmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/O2_qp/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/O2_qp/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/O2_qp/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/O2_qp/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_misc/graphene/graphene.py: driver = 'legacy',
> qmcpack/rsqmc_misc/graphene/graphene.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond_radial_density/diamond_spin.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond_lowdin/diamond.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond_lowdin/diamond_spin.py: driver = 'legacy',
> qmcpack/rsqmc_misc/diamond_lowdin/diamond_spin.py: driver = 'legacy',
> qmcpack/rsqmc_misc/c20/c20.py: driver = 'legacy',
> qmcpack/rsqmc_misc/c20/c20.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/01_diamond_dft_vmc/diamond_lda_vmc_batched.py:This example is similar to diamond_lda_vmc.py (legacy drivers)
> qmcpack/rsqmc_quantum_espresso/01_diamond_dft_vmc/diamond_lda_vmc_batched_estimators.py:This example is similar to diamond_lda_vmc.py (legacy drivers)
> qmcpack/rsqmc_quantum_espresso/01_diamond_dft_vmc/diamond_lda_vmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/01_diamond_dft_vmc/diamond_lda_vmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/02_diamond_dft_vmc_twistavg/diamond_lda_vmc_twistavg.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/02_diamond_dft_vmc_twistavg/diamond_lda_vmc_twistavg.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/03_diamond_dft_dmc_textrap/diamond_lda_dmc_textrap.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_espresso/03_diamond_dft_dmc_textrap/diamond_lda_dmc_textrap.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/02_o2_selci_qmc/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/02_o2_selci_qmc/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/02_o2_selci_qmc/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/02_o2_selci_qmc/o2_selci_vmc_dmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_quantum_package/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/01_h2o_hf_qmc/h2o_ae_hf_qmc.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/02_diamond_hf_qmc/diamond_pp_hf_twistavg.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/02_diamond_hf_qmc/diamond_pp_hf_twistavg_prim.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/02_diamond_hf_qmc/diamond_pp_hf_gamma.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/02_diamond_hf_qmc/diamond_pp_hf_gamma.py: driver = 'legacy',
> qmcpack/rsqmc_pyscf/02_diamond_hf_qmc/diamond_pp_hf_gamma.py: driver = 'legacy’,
>