Solve issue when inserting a point along a non-manifold edge with 2 singular extremities

[Algiane]

Change the return value when BezierNom is called along a non-manifold edge with 2 singular extremities.

If we return 1. The point is inserted along the nom edge but its normals have not been computed (so they can be NaN).

An example of error can be found when running the ls-DisIn-cubegeom-metric-fields-5 test case of ParMmg.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 50.45%. Comparing base (af80663) to head (1e303f8). Report is 2 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #287 +/- ## ======================================== Coverage 50.45% 50.45% ======================================== Files 177 177 Lines 47239 47239 Branches 10272 10272 ======================================== + Hits 23834 23836 +2 + Misses 15673 15671 -2 Partials 7732 7732 ```

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[corentin-prigent]

Thanks !