add fail on edge case in Mesh Data

[Yurlungur]

PR Summary

As discussed in MR #1060 and in the parthenon call, there are edge cases when you add mesh data on a partition. This just prevents you from doing that.

PR Checklist

• Code passes cpplint
• New features are documented.
• Adds a test for any bugs fixed. Adds tests for new features.
• Code is formatted
• Changes are summarized in CHANGELOG.md
• Change is breaking (API, behavior, ...)
  • Change is additionally added to CHANGELOG.md in the breaking section
  • PR is marked as breaking
  • Short summary API changes at the top of the PR (plus optionally with an automated update/fix script)
• CI has been triggered on Darwin for performance regression tests.
• Docs build
• (@lanl.gov employees) Update copyright on changed files

[lroberts36]

LGTM

[pgrete]

Does the comment above still properly reflect this check (basically telling future us' if there's still a need to fix sth)?

[Yurlungur]

Does the comment above still properly reflect this check (basically telling future us' if there's still a need to fix sth)?

It's still relevant if we ever want to make Add work on subsets of the mes. So I'd rather keep it.