Make vof dcdd optional

[AmishgaAlphonius]

Description

It was noticed that using the discontinuity-capturing directional dissipation (DCDD) stabilization was not necessarily helpful for all VOF simulations. With this PR, the stabilization term is now optional. It can be enabled/disabled with the help of a boolean parameter (vof dcdd stabilization) in the stabilization subsection.

Testing

All failing tests because of the disabled DCDD stabilization term were updated and a new application test (gls_droplet_marangoni_effect_with_dcdd_stabilization) has been added with the stabilization enabled.

Documentation

Stabilization documentation has been updated.

Checklist (will be removed when merged)

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Code related list:

• All in-code documentation related to this PR is up to date (Doxygen format)
• Lethe documentation is up to date
• The branch is rebased onto master
• Code is indented with indent-all and .prm files (examples and tests) with prm-indent
• If parameters are modified, the tests and the documentation of examples are up to date
• Changelog (CHANGELOG.md) is up to date if the refactor affects the user experience or the codebase

Pull request related list:

• No other PR is open related to this refactoring
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• There are at least 2 reviewers (or 1 if small feature) excluding the responsible for the merge
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• If any future works is planed, an issue is opened
• The PR description is cleaned and ready for merge

[blaisb]

I am not sure it's a good idea to change the default behavior to no dcdd. Let's keep it enabled (it's been enabled for a year now) and until we figure out when it's good and when it's bad.

[hepap]

Nicely done :) It's good to have the option now!