Test more cases of handling GROMACS residue IDs

[mattwthompson]

Description

Does something with #1016

Fixes #1028

Checklist

• Add tests
  • residue IDs offset from 1
  • residue IDs not specified in input
  • some, but not all, residue IDs specified in input
  • residue IDs > 99,999
  • discontinuous residue IDs
• Consider offering a way for users to re-index (i.e. to avoid zero or negative residue IDs)
• Lint
• Update docstrings
  • Document current behavior and what is currently undefined

[mattwthompson]

FTR: Any removed tests are duplicated; some amount of this file is just leftover from a botched merge some time ago

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.38%. Comparing base (426e3eb) to head (197240d).
Report is 26 commits behind head on main.

Additional details and impacted files

[mattwthompson]

This fixes #1028; running that script produces a file with the IDs incremented on the second molecule:

Generated by Interchange
6
    1MOL0     O    1   0.089   0.885   0.898
    1MOL0     H    2   0.170   0.538   0.836
    1MOL0     H    3   0.586   0.616   0.386
    2MOL0     O    4   0.552   0.965   0.526
    2MOL0     H    5   0.408   0.095   0.491
    2MOL0     H    6   0.879   0.165   0.706
  5.0000000  5.0000000  5.0000000

[j-wags]

@Yoshanuikabundi Could you give this a review when you get a chance?