VOF operations changes

[mbkuhn]

Summary

• deprecate vof-only sharpening
• add replace mask
• make VOF advection into an operator applied from n to n+1

Pull request type

Please check the type of change introduced:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

Checklist

The following is included:

• new unit-test(s)
• new regression test(s)
• documentation for new capability

This PR was tested by running:

• the unit tests
  • on GPU
  • on CPU
• the regression tests
  • on GPU
  • on CPU

Additional background

Trying to keep the PRs small for incorporating the multiphase hybrid changes into main.

[mbkuhn]

@moprak-nrel or @gdeskos, could you give your approval to this? Most of the changes are only to do with multiphase hybrid work, which only affects me. The one aspect of the functionality that still applies during normal standalone operation is that the VOF advection step doesn't work with only the new state of the variable, it starts with the old, applies operations to the nph state as a working copy, then updates the new state. I ran the reg tests and they all passed.