Bugfix: Fix issue with using relative residual tolerance in bicgstab solver

[lroberts36]

PR Summary

Previously the pointer to the mesh was captured by reference in the task list, which apparently went stale by the time the task list was run and the returned cell count was undefined(?). Now we explicitly pass the mesh pointer to the task.

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

[Yurlungur]

LGTM