common.jobs.approx_neb.py and ase.schemas.py fixes

[RobertaPascazio]

Summary

Fixes for multiple working ions in host structure.

• Lowered tolerance on host structure matching.
• This fixed the underlying issue with get_hop_distance_from_endpoints: distances were not parsed correctly (i.e., working ion-working ion distances were being calculated between all working ions).
• Left some dependencies in case we want to introduce logging for those specific errors (e.g., get_hop_distance_from_endpoints failure in case of multiple working ions detected)
• Changed ValueEnum import in src/atomate2/ase/schemas.py (from emmet.core.utils to emmet.core.types.enums).

Checklist

• All linting and tests passed in pre-commit.