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

• [x] Code passes cpplint
• [ ] New features are documented.
• [ ] Adds a test for any bugs fixed. Adds tests for new features.
• [x] Code is formatted
• [x] 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

[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.