Pull in AMReX-Codes/amrex#4948

## Summary

Add the `Allocator` template, so we can use this with polymorphic PCs
(and generally any PC that does not use the default allocator).

## Additional background

Same as  #4776 #4948 but for SENSEI.

## Checklist

The proposed changes:
- [ ] fix a bug or incorrect behavior in AMReX
- [x] add new capabilities to AMReX
- [ ] changes answers in the test suite to more than roundoff level
- [ ] are likely to significantly affect the results of downstream AMReX
users
- [ ] include documentation in the code and/or rst files, if appropriate

Pull in the merged PRs
- [x] AMReX-Codes/amrex#4948
- [x] AMReX-Codes/amrex#4949

for #6374

- [x] replace all templates
- [x] `setArena`, update `define()` calls, etc.
- [x] remove unnecessary classes (e.g.,
`PinnedMemoryParticleContainer`): if `WarpXParticleContainer` had not
purely virtual functions, this would be cleaner to implement (adding a
`WarpXParticleContainer::Base` for now).
- [x] test again on GPU at runtime
- [x] rebase on AMReX-Codes/pyamrex#428
- [x] rebase on AMReX-Codes/amrex#4771 and
simplify `make_alike` calls
- [x] rebase on AMReX-Codes/amrex#4776 and
AMReX-Codes/amrex#4948 and
AMReX-Codes/amrex#4949

Pull in the merged PRs
- [x] AMReX-Codes/amrex#4948
- [x] AMReX-Codes/amrex#4949

for BLAST-WarpX#6374

- [x] replace all templates
- [x] `setArena`, update `define()` calls, etc.
- [x] remove unnecessary classes (e.g.,
`PinnedMemoryParticleContainer`): if `WarpXParticleContainer` had not
purely virtual functions, this would be cleaner to implement (adding a
`WarpXParticleContainer::Base` for now).
- [x] test again on GPU at runtime
- [x] rebase on AMReX-Codes/pyamrex#428
- [x] rebase on AMReX-Codes/amrex#4771 and
simplify `make_alike` calls
- [x] rebase on AMReX-Codes/amrex#4776 and
AMReX-Codes/amrex#4948 and
AMReX-Codes/amrex#4949