Introduce global Lattice type

[ye-luo]

Proposed changes

Although the code seems to allow different places to define its own CrystalLattice<T> type. At the end of day, all of PtclOnLatticeTraits::ParticleLayout ParticleSet::ParticleLayout effectively refer to CrystalLattice<OHMMS_PRECISION, OHMMS_DIM>. This PR define a global type Lattice as a replacement of all the above and I will eventually change it to CrystalLattice<OHMMS_PRECISION_FULL, OHMMS_DIM> in #5350.

What type(s) of changes does this code introduce?

• Refactoring (no functional changes, no api changes)

Does this introduce a breaking change?

• No

What systems has this change been tested on?

epyc-server

Checklist

• Yes. This PR is up to date with current the current state of 'develop'
• Yes. Code added or changed in the PR has been clang-formatted

[ye-luo]

Test this please

[prckent]

I'll wait to review this when it is no longer marked as draft, but I am very much on board with the change.
It will take a couple of PRs to get all the changes in , but the one thing I would like to see is a before/after of our full set of performance ctest results on at least CPU (NiO bulk, graphene and C molecule). Any degradation should be minimal. Anything severe would indicate we have to, e.g., update Coulomb handling to convert to float more promptly.

[PDoakORNL]

test this please

[prckent]

LGTM

Definitely an improvement, imo. Expressions like "using ParticleLayout = Lattice;" read oddly currently. Renaming &/or more simplification possible in future.

[PDoakORNL]

test this please