Use boost program options for ExtractSurface2DCFS

Issue/feature addressed

The ExtractSurface2DCFS utility used an ad-hoc approach to handle the program input

Proposed solution

Use the boost program options library, consistent with the rest of the code.

Implementation

Modified program: ExtractSurface2DCFS.cpp to define required parameters and parse command-line arguments using Boost program options.

Tests

Not provided in the original MR (!1323 (merged))

Notes

Checklist

• Functions and classes, or changes to them, are documented.
• User guide/documentation is updated.
• Changelog is updated.
• Suitable tests added for new functionality.
• Contributed code is correctly formatted. (See the contributing guidelines).
• License added to any new files.
• No extraneous files have been added (e.g. compiler output or test data files).

Warning

On the 19.07 the code formatting (code style) was standardised using clang-format, over the whole Nektar++ code. This means changes in your branch will conflict with formatting changes on the master branch. To resolve these conflicts , see #295 (closed)