Need to consolidate TWF/WFC::evalGradSource

After the removal of finite difference https://github.com/QMCPACK/qmcpack/pull/5380, certain clean up can happen
1. Removal of `ions` particle set passing as an argument. This was needed because each walker needed a separate `ions` to operate moves. Since it is no longer needed, each component that involves ions can use its internal const reference to ions.
2. electron particleset should made possible if possible.
3. There are two evalGradSource functions and preferably reduce to one.
4. Remove all the clones of `ions`.